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Showing posts with label PUZZLE. Show all posts
Showing posts with label PUZZLE. Show all posts
Wednesday, July 3, 2013
SUDOKU, PUZZLES
Free math problem solver
Free math problem solver
The free math problem solver below is a sophisticated tool that will solve any math problems you enter quickly and then show you the answer.
I recommend that you use it only to check your own work because occasionally, it might generate strange results
After you enter your math problems, click on "Math Format" to make sure you have effectively entered the math problem you really want it to solve
You can also enter word problems, but don't be too fancy. Use plenty of math operators and keep it as simple as possible
If you want step by step solution after the final answer is entered, click on "View Steps"
This will take you to the developer's site where you sign in. A modest fee may be required to view all steps
Enjoy this online math problem solver!
Need a math tutor?
Get an answer in 10 minutes or less from a math expert!
Get an answer in 10 minutes or less from a math expert!
Justanswer features top-notch math experts handpicked by personnel after they have taken and passed a rigourous math test and after their credentials have been verified by a third party
Most math experts have bachelor's or master's degree in math or a related field
I am also an expert for justanswer. If you want me to answer your questions, sign in, browse the list of math experts, select my name or ask for me (Jetser Carasco) before sending your question(s)
The formula for percentage is the following and it should be easy to use
The formula for percentage is the following and it should be easy to use:
Study it below carefully before looking at the examples
We will take examples to illustrate.Let us start with the formula on the left
An important thing to remember: Cross multiply
It means to multiply the numerator of one fraction by the denominator of the other fraction
Examples #1:
25 % of 200 is____
In this problem, of = 200, is = ?, and % = 25
We get:
is/200 = 25/100
Since is in an unknown, you can replace it by y to make the problem more familiar
y/200 = 25/100
Cross multiply to get y × 100 = 200 × 25
y × 100 = 5000
Divide 5000 by 100 to get y
Since 5000/100 = 50, y = 50
So, 25 % of 200 is 50
Examples #2:
What number is 2% of 50 ?
This is just another way of saying 2% of 50 is___
So, set up the proportion as example #1:
is/50 = 2/100
Replace is by y and cross multiply to get:
y × 100 = 50 × 2
y × 100 = 100
Since 1 × 100 = 100, y = 1
Therefore, 1 is 2 % of 50
Examples #3:
24% of___ is 36
This time, notice that is = 36, but of is missing
After you set up the formula, you get:
36/of = 24/100
Replace of by y and cross multiply to get:
36/y = 24/100
y × 24 = 36 × 100
y × 24 = 3600
Divide 3600 by 24 to get y
3600/24 = 150, y = 150
Therefore, 24 % of 150 is 36
Now, we will take examples to illustrate how to use the formula for percentage on the right
Examples #4:
To use the other formula that says part and whole, just remember the following:
The number after of is always the whole
The number after is is always the part
If I say 25 % of___ is 60, we know that the whole is missing and part = 60
Your proportion will will like this:
60/whole = 25/100
After cross multiplying, we get:
whole × 25 = 60 × 100
whole × 25 = 6000
Divide 6000 by 25 to get whole
6000/25 = 240, so whole = 240
Therefore, 25 % of 240 is 60
Examples #5:
___% of 45 is 9
Here whole = 45 and part = 9, but % is missing
We get:
9/45 = %/100
Replacing % by x and cross multiplying gives:
9 × 100 = 45 × x
900 = 45 × x
Divide 900 by 45 to get x
900/45 = 20, so x = 20
Here we go!. I hope these formula for percentage were helpful.
We will take examples to illustrate.Let us start with the formula on the left
An important thing to remember: Cross multiply
It means to multiply the numerator of one fraction by the denominator of the other fraction
Examples #1:
25 % of 200 is____
In this problem, of = 200, is = ?, and % = 25
We get:
is/200 = 25/100
Since is in an unknown, you can replace it by y to make the problem more familiar
y/200 = 25/100
Cross multiply to get y × 100 = 200 × 25
y × 100 = 5000
Divide 5000 by 100 to get y
Since 5000/100 = 50, y = 50
So, 25 % of 200 is 50
Examples #2:
What number is 2% of 50 ?
This is just another way of saying 2% of 50 is___
So, set up the proportion as example #1:
is/50 = 2/100
Replace is by y and cross multiply to get:
y × 100 = 50 × 2
y × 100 = 100
Since 1 × 100 = 100, y = 1
Therefore, 1 is 2 % of 50
Examples #3:
24% of___ is 36
This time, notice that is = 36, but of is missing
After you set up the formula, you get:
36/of = 24/100
Replace of by y and cross multiply to get:
36/y = 24/100
y × 24 = 36 × 100
y × 24 = 3600
Divide 3600 by 24 to get y
3600/24 = 150, y = 150
Therefore, 24 % of 150 is 36
Now, we will take examples to illustrate how to use the formula for percentage on the right
Examples #4:
To use the other formula that says part and whole, just remember the following:
The number after of is always the whole
The number after is is always the part
If I say 25 % of___ is 60, we know that the whole is missing and part = 60
Your proportion will will like this:
60/whole = 25/100
After cross multiplying, we get:
whole × 25 = 60 × 100
whole × 25 = 6000
Divide 6000 by 25 to get whole
6000/25 = 240, so whole = 240
Therefore, 25 % of 240 is 60
Examples #5:
___% of 45 is 9
Here whole = 45 and part = 9, but % is missing
We get:
9/45 = %/100
Replacing % by x and cross multiplying gives:
9 × 100 = 45 × x
900 = 45 × x
Divide 900 by 45 to get x
900/45 = 20, so x = 20
Here we go!. I hope these formula for percentage were helpful.
Really Hard Riddles
Top 20 Really Hard Riddles
Really Hard Riddles 1 : September Riddle
Difficulty ★★★★☆ Popularity ★★★☆☆
man gave one son 10 cents and another son was given 15 cents. What time is it?
For Answers/Discussion : Click Here
==============================================
Really Hard Riddles 2 : Famous Probability puzzle SHOOT
Difficulty ★★★★☆ Popularity ★★★★☆
Mr. Black, Mr. Gray, and Mr. White are fighting in a truel. They each get a gun and take turns shooting at each other until only one person is left. Mr. Black, who hits his shot 1/3 of the time, gets to shoot first. Mr. Gray, who hits his shot 2/3 of the time, gets to shoot next, assuming he is still alive. Mr. White, who hits his shot all the time, shoots next, assuming he is also alive. The cycle repeats. If you are Mr. Black, where should you shoot first for the highest chance of survival?
For Answers/Discussion : Click Here
==============================================
Really Hard Riddles 3 : Writers Riddle
Difficulty ★★★★☆ Popularity ★★★★☆
What work can one never finish?
For Answers/Discussion : Click Here
==============================================
Really Hard Riddles 4 : Aeroplane Hijack puzzle
Difficulty ★★★★★ Popularity ★★★★☆
A man hijacks an aeroplane transporting both passengers(8 of them) and valuable cargo. After taking the cargo, the man demands nine parachutes, puts one of them on, and jumps, leaving the other eight behind. Why did he want eight?
For Answers/Discussion : Click Here
==============================================
Really Hard Riddles 5 : Cipher Puzzle
Difficulty ★★★★☆ Popularity ★★★★★
What does this message say?
G T Y O R J O T E O U I A B G T
Hint
Count the letters and try splitting the letters up into groups.
For Answers/Discussion : Click Here
==============================================
Really Hard Riddles 6 : Pyramid Number Puzzle
Difficulty ★★★★☆ Popularity ★★★★★
The below is a number puzzle. It should be read left to right, top to bottom.
1
1 1
2 1
1 2 1 1
1 1 1 2 2 1
? ? ? ? ? ?
? ? ? ? ? ? ? ?
Question 1: What is the next two rows of numbers?
Question 2: How was this reached?
For Answers/Discussion : Click Here
==============================================
Really Hard Riddles 7 : Unique Riddle
Difficulty ★★★★★ Popularity ★★★☆☆
What is the unique characteristic of the following words:
coughing, thirsty, defiant
For Answers/Discussion : Click Here
==============================================
Really Hard Riddles 8 : CAT EXAM Riddle
Difficulty ★★★★☆ Popularity ★★★★☆
There is a shop that reads:
Buy 1 for $1.00
10 for $2.00
100 for $3.00
I needed 913 and still only paid $3.00. How could this be financially viable for the shop-keeper?
For Answers/Discussion : Click Here
==============================================
Really Hard Riddles 9 : What Am I Puzzle
Difficulty ★★★★☆ Popularity ★★★★☆
If you throw me from the window,
I will leave a grieving wife.
Bring me back, but in the door, and
You'll see someone giving life!
What am I?
For Answers/Discussion : Click Here
==============================================
Really Hard Riddles 10 : Mathematical Riddle
Difficulty ★★★★★ Popularity ★★★☆☆
Using only two 2's and any combination of mathematical signs, symbols and functions can you make 5?
For Answers/Discussion : Click Here
==============================================
Really Hard Riddles 11 : Famous Elevator Puzzle
Difficulty ★★★★☆ Popularity ★★★★☆
A man who lives on the tenth floor takes the elevator down to the first floor every morning and goes to work. In the evening, when he comes back; on a rainy day, or if there are other people in the elevator, he goes to his floor directly. Otherwise, he goes to the seventh floor and walks up three flights of stairs to his apartment.
Can you explain why?
For Answers/Discussion : Click Here
==============================================
Really Hard Riddles 12 : Mystery Puzzle Sherlock Holmes
Difficulty ★★★★☆ Popularity ★★★☆☆
One snowy night, Sherlock Holmes was in his house sitting by a fire. All of a sudden a snowball came crashing through his window, breaking it. Holmes got up and looked out the window just in time to see three neighborhood kids who were brothers run around a corner. Their names were John Crimson, Mark Crimson and Paul Crimson.
The next day Holmes got a note on his door that read '? Crimson. He broke your window.'
Which of the three Crimson brothers should Sherlock Holmes question about the incident?
For Answers/Discussion : Click Here
==============================================
Really Hard Riddles 13 : Which Is The Odd One Out
Difficulty ★★★★★ Popularity ★★★☆☆
Find The Odd One Out
1.FLOW
2.SNIP
3.TRAP
4.DRAW
5.BACK
For Answers/Discussion : Click Here
==============================================
Really Hard Riddles 14 : Answer This Joke Riddle
Difficulty ★★★★☆ Popularity ★★★★★
Why is 6 afraid of 7?
For Answers/Discussion : Click Here
==============================================
Really Hard Riddles 15 : Hard Math Riddle
Difficulty ★★★★☆ Popularity ★★★★★
Take 9 from 6, 10 from 9, 50 from 40 and leave 6.
How Come ??
For Answers/Discussion : Click Here
==============================================
Really Hard Riddles 16 : Death Mystery Riddle
Difficulty ★★★★☆ Popularity ★★★★☆
Two men are in a desert. They both have packs on. One of the guys is dead. The guy who is alive has his pack open, the guy who is dead has his pack closed. What is in the pack?
For Answers/Discussion : Click Here
==============================================
Really Hard Riddles 17 : Hardest Math Riddle
Difficulty ★★★★★ Popularity ★★★★★
Create a number using only the digits 4,4,3,3,2,2,1 and 1. So i can only be eight digits. You have to make sure the ones are separated by one digit, the twos are separated by two digits the threes are separated with three digits and the fours are separated by four digits
For Answers/Discussion : Click Here
==============================================
Really Hard Riddles 18 : Puzzle In A Puzzle
Difficulty ★★★★☆ Popularity ★★★★★
What are the next two letters in the following series and why?
W A T N T L I T F S _ _
*Hint: Check Puzzle Title
For Answers/Discussion : Click Here
==============================================
Really Hard Riddles 19 : Alexander Puzzle
Difficulty ★★★★☆ Popularity ★★★★★
Alexander is stranded on an island covered in forest.
One day, when the wind is blowing from the west, lightning strikes the west end of the island and sets fire to the forest. The fire is very violent, burning everything in its path, and without intervention the fire will burn the whole island, killing the man in the process.
There are cliffs around the island, so he cannot jump off.
How can the Alexander survive the fire? (There are no buckets or any other means to put out the fire)
For Answers/Discussion : Click Here
==============================================
Really Hard Riddles 20 : Challenging Puzzle
Difficulty ★★★★☆ Popularity ★★★★★
Outside a room there are three light switches. One of switch is connected to a light bulb inside the room.
Each of the three switches can be either 'ON' or 'OFF'.
You are allowed to set each switch the way you want it and then enter the room(note: you can enter the room only once)
Your task is to then determine which switch controls the bulb ??
For Answers/Discussion : Click Here
==============================================
Really Hard Riddles 1 : September Riddle
Difficulty ★★★★☆ Popularity ★★★☆☆
man gave one son 10 cents and another son was given 15 cents. What time is it?
For Answers/Discussion : Click Here
==============================================
Really Hard Riddles 2 : Famous Probability puzzle SHOOT
Difficulty ★★★★☆ Popularity ★★★★☆
Mr. Black, Mr. Gray, and Mr. White are fighting in a truel. They each get a gun and take turns shooting at each other until only one person is left. Mr. Black, who hits his shot 1/3 of the time, gets to shoot first. Mr. Gray, who hits his shot 2/3 of the time, gets to shoot next, assuming he is still alive. Mr. White, who hits his shot all the time, shoots next, assuming he is also alive. The cycle repeats. If you are Mr. Black, where should you shoot first for the highest chance of survival?
For Answers/Discussion : Click Here
==============================================
Really Hard Riddles 3 : Writers Riddle
Difficulty ★★★★☆ Popularity ★★★★☆
What work can one never finish?
For Answers/Discussion : Click Here
==============================================
Really Hard Riddles 4 : Aeroplane Hijack puzzle
Difficulty ★★★★★ Popularity ★★★★☆
A man hijacks an aeroplane transporting both passengers(8 of them) and valuable cargo. After taking the cargo, the man demands nine parachutes, puts one of them on, and jumps, leaving the other eight behind. Why did he want eight?
For Answers/Discussion : Click Here
==============================================
Really Hard Riddles 5 : Cipher Puzzle
Difficulty ★★★★☆ Popularity ★★★★★
What does this message say?
G T Y O R J O T E O U I A B G T
Hint
Count the letters and try splitting the letters up into groups.
For Answers/Discussion : Click Here
==============================================
Really Hard Riddles 6 : Pyramid Number Puzzle
Difficulty ★★★★☆ Popularity ★★★★★
The below is a number puzzle. It should be read left to right, top to bottom.
1
1 1
2 1
1 2 1 1
1 1 1 2 2 1
? ? ? ? ? ?
? ? ? ? ? ? ? ?
Question 1: What is the next two rows of numbers?
Question 2: How was this reached?
For Answers/Discussion : Click Here
==============================================
Really Hard Riddles 7 : Unique Riddle
Difficulty ★★★★★ Popularity ★★★☆☆
What is the unique characteristic of the following words:
coughing, thirsty, defiant
For Answers/Discussion : Click Here
==============================================
Really Hard Riddles 8 : CAT EXAM Riddle
Difficulty ★★★★☆ Popularity ★★★★☆
There is a shop that reads:
Buy 1 for $1.00
10 for $2.00
100 for $3.00
I needed 913 and still only paid $3.00. How could this be financially viable for the shop-keeper?
For Answers/Discussion : Click Here
==============================================
Really Hard Riddles 9 : What Am I Puzzle
Difficulty ★★★★☆ Popularity ★★★★☆
If you throw me from the window,
I will leave a grieving wife.
Bring me back, but in the door, and
You'll see someone giving life!
What am I?
For Answers/Discussion : Click Here
==============================================
Really Hard Riddles 10 : Mathematical Riddle
Difficulty ★★★★★ Popularity ★★★☆☆
Using only two 2's and any combination of mathematical signs, symbols and functions can you make 5?
For Answers/Discussion : Click Here
==============================================
Really Hard Riddles 11 : Famous Elevator Puzzle
Difficulty ★★★★☆ Popularity ★★★★☆
A man who lives on the tenth floor takes the elevator down to the first floor every morning and goes to work. In the evening, when he comes back; on a rainy day, or if there are other people in the elevator, he goes to his floor directly. Otherwise, he goes to the seventh floor and walks up three flights of stairs to his apartment.
Can you explain why?
For Answers/Discussion : Click Here
==============================================
Really Hard Riddles 12 : Mystery Puzzle Sherlock Holmes
Difficulty ★★★★☆ Popularity ★★★☆☆
One snowy night, Sherlock Holmes was in his house sitting by a fire. All of a sudden a snowball came crashing through his window, breaking it. Holmes got up and looked out the window just in time to see three neighborhood kids who were brothers run around a corner. Their names were John Crimson, Mark Crimson and Paul Crimson.
The next day Holmes got a note on his door that read '? Crimson. He broke your window.'
Which of the three Crimson brothers should Sherlock Holmes question about the incident?
For Answers/Discussion : Click Here
==============================================
Really Hard Riddles 13 : Which Is The Odd One Out
Difficulty ★★★★★ Popularity ★★★☆☆
Find The Odd One Out
1.FLOW
2.SNIP
3.TRAP
4.DRAW
5.BACK
For Answers/Discussion : Click Here
==============================================
Really Hard Riddles 14 : Answer This Joke Riddle
Difficulty ★★★★☆ Popularity ★★★★★
Why is 6 afraid of 7?
For Answers/Discussion : Click Here
==============================================
Really Hard Riddles 15 : Hard Math Riddle
Difficulty ★★★★☆ Popularity ★★★★★
Take 9 from 6, 10 from 9, 50 from 40 and leave 6.
How Come ??
For Answers/Discussion : Click Here
==============================================
Really Hard Riddles 16 : Death Mystery Riddle
Difficulty ★★★★☆ Popularity ★★★★☆
Two men are in a desert. They both have packs on. One of the guys is dead. The guy who is alive has his pack open, the guy who is dead has his pack closed. What is in the pack?
For Answers/Discussion : Click Here
==============================================
Really Hard Riddles 17 : Hardest Math Riddle
Difficulty ★★★★★ Popularity ★★★★★
Create a number using only the digits 4,4,3,3,2,2,1 and 1. So i can only be eight digits. You have to make sure the ones are separated by one digit, the twos are separated by two digits the threes are separated with three digits and the fours are separated by four digits
For Answers/Discussion : Click Here
==============================================
Really Hard Riddles 18 : Puzzle In A Puzzle
Difficulty ★★★★☆ Popularity ★★★★★
What are the next two letters in the following series and why?
W A T N T L I T F S _ _
*Hint: Check Puzzle Title
For Answers/Discussion : Click Here
==============================================
Really Hard Riddles 19 : Alexander Puzzle
Difficulty ★★★★☆ Popularity ★★★★★
Alexander is stranded on an island covered in forest.
One day, when the wind is blowing from the west, lightning strikes the west end of the island and sets fire to the forest. The fire is very violent, burning everything in its path, and without intervention the fire will burn the whole island, killing the man in the process.
There are cliffs around the island, so he cannot jump off.
How can the Alexander survive the fire? (There are no buckets or any other means to put out the fire)
For Answers/Discussion : Click Here
==============================================
Really Hard Riddles 20 : Challenging Puzzle
Difficulty ★★★★☆ Popularity ★★★★★
Outside a room there are three light switches. One of switch is connected to a light bulb inside the room.
Each of the three switches can be either 'ON' or 'OFF'.
You are allowed to set each switch the way you want it and then enter the room(note: you can enter the room only once)
Your task is to then determine which switch controls the bulb ??
For Answers/Discussion : Click Here
==============================================
Fun math puzzles
Fun math puzzles
I try my best to provide you with fun math puzzles. Fun does not necessarily means easy. As a math major, anything that becomes challenging is fun for me.
The puzzles on this page are warm ups. More complicated puzzles will be added on a regular basis
Let's get started with some fun math puzzles!
Puzzle #1:
Use four 5s and some of the symbols +, ×, −, and ÷ to give expressions for 0, 1, 2, and 5
Puzzle #2:
Use the two isosceles triangles below to make a star?
It takes 1629 digits to number the pages of a book. How many pages does the book have?
Puzzle #4:
Use only 4 straight lines to cut a pizza into 11 pieces?
Puzzle #5:
would you rather work for 30 days and get paid 5 millions dollars, or be paid 1 cent the first day, 2 cents the second day, 4 cents the third day, and so on...?
Puzzle #6:
Place 10 dishes along the 4 edges of a table so that each edge has the same amount of dishes
Puzzle #7:
In a family with 4 siblings, John is older than Mary, Peter is younger than John, Mary is older than Peter, and Sarah is older than John. Who is the second oldest in the family? Who is the youngest?
Puzzle #1 solution:
5 − 5 + 5 − 5 = 0
5 − 5 + 5 ÷5 = 1
5 ÷5 + 5 ÷5 = 1 + 1 = 2
5 × (5 − 5) + 5 = 5
Puzzle #2 solution:
From page #1 to page # 9, there are 9 pages
From page #10 to page # 99, there are 90 pages. However, since each page number has 2 digits, there are 180 digits from page # 10 to page # 99
From page #100 to page # 999, there are 900 pages. However, since each page number has 3 digits, there are 2700 digits from page # 100 to page # 999
Since there are 1629 digits, we know so far that number of pages is less than 900
Now, we need to find out how many digits there are for those pages greater than 99 or those pages with 3 digits
Since there are 189 digits for pages with less than 3 digits, we can subtract 189 from 1629 digits to find the number of pages with 3 digits
1629 − 189 = 1440
1440 represents the pages with 3 digits, so number of pages with 3 digits = 1440/3 = 480
Thus, total number of pages = 480 + 90 + 9 = 579 pages
Puzzle #4 solution:
The trick is to find out how much money you make in 30 days if you get 1 cent the first day, 2 cents the second day, 4 cents the third day, and so on... Day 1: 1 cents
Day 2: 2 cents
Day 3: 4 cents
Day 4: 8 cents
Day 5: 16 cents
Day 6: 32 cents
Day 7: 64 cents
Day 8: 128 cents
Day 9: 256 cents
-------
-------
-------
-------
Keep mutliplying by 2
-------
-------
-------
-------
Day 30: 536,870,912 cents
536,870,912 cents/100 = 5,368,709.12 dollars and 5,368,709.12 is bigger than 5,000,000
Therefore, you are better off taking 1 cent the first day, 2 cents the second day, 4 cents the third day, and so on... until the 30th day
Puzzle #6:
If the blue rectangle represents the table and the red circles represent dishes, here is the solution
Puzzle #7:
In a family with 4 siblings, John is older than Mary, Peter is younger than John, Mary is older than Peter, and Sarah is older than John. Who is the second oldest in the family? Who is the youngest?
This puzzle. You solve it! Yes, the first person who solves this fun math puzzle with a detailed solution, will have his solution posted on this page with his name in parenthesis. As an added bonus, you can get my fractions ebook plus all bonuses with a donation of your choice
All other persons who solve this puzzle will not have their names listed, but they can get my fractions ebook and the bonuses with a donation of at least 10 dollars instead of paying the regular price of 29 dollars!
Here is the process to follow:
Send the solution using the form here
If you have the correct solution, I will contact you with further instructions.
If you love these fun math puzzles, stay tune. This page will be updated with fun math puzzles on a regular basis!
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