# fill a bathtub by running water

You want to fill a bathtub by running water from both the hot and cold taps. The hot tap takes 6 minutes to fill the tub alone and the cold tap takes 4 minutes to fill alone. So you turn them both on at the same time but you are unaware that you left the plug out. The plug empties the tub in 12 minutes. How long will it take to fill the tub?

# There are two hourglasses

There are two hourglasses. The small one can measure 5 minutes and the large one can measure 7 minutes. How can we measure 16 minutes with 2 hourglasses running together? (If one of the hourglasses finishes leaking, then it must be flipped over immediately to keep it running. )

# Wine Barrel

There is a barrel with no lid and some wine in it.
“This barrel of wine is more than half full,” said Kiran.
“No it’s not,” says Rahul. “It’s less than half full.”

Without any measuring implements and without removing any wine from the barrel, how can they easily determine who is correct?

# A Dog, a Cow and a Goat were stolen

A Dog, a Cow and a Goat were stolen. Three suspects got caught: Rahul, Mithun and Ram. Each person stole one animal, but we do not know who stole which. Here are the investigation statements.

Rahul said: Ram stole the Dog.

Mithun said: Ram stole the Cow.

Ram said: They both were lying. I did not steal the Dog or the Cow.

Later on, the police found out the man who stole the goat told a lie. The man who stole the dog told the truth. Can you find out who stole which?

# Snail in the well puzzle

A snail is at the bottom of a well 30 feet deep. It crawls up 3 feet each day, but at night, it slips down 2 feet. How long does it take for the snail to crawl out the well?

# Which of the following formula is different from others

Which of the following formula is different from others?

• 100/11
• 100/22
• 100/33
• 100/44
• 100/55
• 100/66
• 100/77
• 100/88
• 100/99

# Take a look at the following sentences

Take a look at the following sentences:

• The number of times the digit 0 appears in this puzzle is _____.
• The number of times the digit 1 appears in this puzzle is _____.
• The number of times the digit 2 appears in this puzzle is _____.
• The number of times the digit 3 appears in this puzzle is _____.
• The number of times the digit 4 appears in this puzzle is _____.
• The number of times the digit 5 appears in this puzzle is _____.
• The number of times the digit 6 appears in this puzzle is _____.
• The number of times the digit 7 appears in this puzzle is _____.
• The number of times the digit 8 appears in this puzzle is _____.
• The number of times the digit 9 appears in this puzzle is _____.

Fill these sentences with digits such that all the sentences holds true.

# You have two hourglasses

You have two hourglasses: a 7 minute one and an 11 minute one. Using just these hourglasses, how can you accurately measure time 15 minutes?

# You are in a room that has six doors

You are in a room that has six doors. You must pass through all six doors, each door once only, in the correct order. Three are entrances only and three are exits only. Door A must be followed by door B or E; D by A or F; B by C or E; C by D or F;E by B or D; and F by C or D. Also A, F are entrance and B is exit. In what order you must pass through the doors?

# There is a five digit number

There is a five digit number ABCDE (A, B, C, D & E are 5 different single digit numbers). If you multiply this number with 4, you get reverse of the number. Find A, B, C, D & E respectively.

ABCDE * 4 = EDCBA

# Find next number in the series

Find next number in the series.

6 ..25 .. 64 ..81 ..32 ..?

# Find the next letter in this sequence

Find the next letter in this sequence.

F S S E N T T T T T T T T T T T T T T T T T T T T ?

# Divide Water Equally

You have a 12 liter jug, an 8 liter jug, and a 5 liter jug. The 12 liter jug is full, and the other two are empty. How can you divide the 12 liters of water equally (i.e., so two of the jugs have exactly 6 liters of water in them, and the third is empty)?

# You have 5 boxes and each box has 5 marbles

You have 5 boxes and each box has 5 marbles in it. Marbles in 4 bags weight 10g each and in one bag weight 9g each. You don’t know which bag has 9g marbles and you are given a chance to use a weight scale for one time. How can you find the bag with 9g marbles?

# I have classified all the 26 English letters into two groups

I have classified all the 26 English letters into two groups.

• W R T Y U I S F H J K L Z X C V N M
• Q E O P A D G B

On what criteria did I classified these letters?

# An explorer wishes to cross a barren desert

An explorer wishes to cross a barren desert that requires 6 days to cross, but one man can only carry enough food for 4 days. What is the fewest number of other men required to help carry enough food for him to cross?

# A Strange Liar

Ravi is a strange liar. He lies on six days of the week, but on the seventh day he always tells the truth. He made the following statements on three successive days:

Day 1: “I lie on Monday and Tuesday.”
Day 2: “Today, it’s Thursday, Saturday, or Sunday.”
Day 3: “I lie on Wednesday and Friday.”

On which day does Ravi tell the truth?

# Pound of cotton or a Pound of gold

Which would you say is heavier, a pound of cotton or a pound of gold?

# Date of Birth Puzzle

Yesterday in a party, I asked Mr. Shah his birthday. With a mischievous glint in his eyes he replied. “The day before yesterday I was 83 years old and next year I will be 86.” Can you figure out what is the Date of Birth of Mr. Shah? Assume that the current year is 2000.

# Place a mathematical symbol

Place a mathematical symbol between 3 & 7 to get a number which is greater than 3 but lesser than 7.