If it took eight men ten hours to build a wall, how long would it take four men to build it?

You have 10 balls with you. A friend of yours out of nowhere asks you to place those ten balls in five lines such that each of the lines has exactly 4 balls on them. He needs to check your intelligence. Prove him by doing the task.

Christina has four daughters, and each of her daughters has a brother. How many children does Christina have?

Arrange the numbers 1, 2, 3, 4, 5, 6, 7, 8 and 9 above and below the division line in a manner that the thus formed fractions equal to 1/3.

(You can use one number only once)

A game is being played where eight players can last for thirty-five minutes. Six substitutes alternate with each player in this game. Thus, all players are on the pitch for the same amount of time including the substitutes.

For how long is each player on the pitch?

How can a man go eight days without sleep?

Identify the 10 differences between the two given pictures.

I possess a head

I flaunt a tail

But I don't have mouth or legs

Can you find out who I am?

Can you find the thief by just looking at the picture below?

Astrology starts with the alphabet A, Biology starts with B, Psychology with P and Limnology with L.

Can you find an "ology" that begins with a P?