In a rectangular dance hall, how do you place 10 chairs along the walls so that there are an equal number of chairs along each wall?

A man ate 100 apples in the past five days. Each day he ate 6 more apples than the previous day. How many did he eat on the 4th day?

There are 12 kids in a classroom. 6 kids are wearing socks and 4 are wearing shoes. 3 kids are wearing both. How many are bare feet?

There are several books on a bookshelf. If one book is the 4th from the left and 6th from the right, how many books are on the shelf?

A street that’s 30 yards long has a chestnut tree every 6 yards on both sides. How many chestnut trees are on the entire street?

A drove of sheep and chickens have a total of 99 heads and feet. There are twice as many chickens as sheep. How many of each are there?

If the end of the world should come on the first day of a new century, can you say what are the chances that it will happen on a Sunday?

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

A smart landscaper is given the task of placing 4 trees so that they are all the same distance away from each other. How does he do this?

Three kinds of apples are mixed randomly in a box. How many apples must you take out to be sure of having at least two apples of one kind?

A 4-wheel drive car has travelled 10,000 miles using 5 tyres. All tyres have travelled the same distance. How many miles each tyre has run?

There are 6561 balls. Out of them 1 is heavy. Find the minimum number of times the balls have to be weighed for finding out the heavy ball.

What is wrong with the following proof? 2=1 a = b a2 = ab a2 – b2 = ab – b2 (a+b)(a-b) = b(a-b) a + b = b 2b = b 2 = 1

A man has $1.15 in six coins. He can’t make change for a dollar, a half dollar, a quarter, a dime, or a nickel. What coins did he have?

You drive to the store at 20 mph and return by the same route at 30 mph. Discounting the time spent at the store, what was your average speed?