When my father was 31 I was 8. Now he is twice as old as me. How old am I?

Can you find out the missing number?

? 4 5 3 5

9 5 7 10 3

Make a sentence consisting of three words that have the whole alphabet.

There are two candles. Both will only burn exactly for an hour. How will you use these two candles to measure forty-five minutes?

A man had five children. He had $100 with him to give to his children. He decided to start with the youngest child and then give $2 more than each younger child to his next elder child.

For example, if he gives $x to the youngest child, he will give $(x+2) to the next one, $[(x+2) + 2] to the next one and so on.

Can you find out how much did the youngest one receive?

You have two buckets of 11 liters and 6 litres.
How can you measure exactly 8 litres?

Imagine a box with two cogwheels, one big with 24 teeth and one small with 8 teeth. The big one is firmly attached to the center of the box which means it does not turn or move while the small one rotates around the big one.

How many times do you think that the smaller wheel will turn compared to the box when it turns once around the big one?

If you’ve got me, you want to share me; if you share me, you haven’t kept me. What am I?

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?

What is harder to catch the faster you run?