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

Why is it very easy to weigh a fish?

What famous saying does this rebus mean?

COME SERVED <---
COME SERVED
COME SERVED
COME SERVED
COME SERVED

How many times do a clock's hands overlap in a day ?

What is the word or phrase?

One absent-minded ancient philosopher forgot to wind up his only clock in the house. He had no radio, TV, telephone, internet, or any other means for telling time. So he travelled on foot to his friend's place a few miles down the straight desert road. He stayed at his friend's house for the night and when he came back home, he knew how to set his clock. How did he know?

Find the next number in the series below

21 32 54 87 131 ?

What brings you down but never up?

A woman lives in a skyscraper thirty-six floors high and is served by several elevators which stop at each floor going up and down. Each morning she leaves her apartment and goes to one of the elevators. Whichever one she takes is three times more likely to be going up than down. Why?

Two prisoners Jack and Jill are locked in a cell.
There is open window approx 40 feet above the ground of the cell.
They are never able to reach there.

Then they plan to escape by a tunnel and they start digging out.
After digging for more than 20 days, Jill comes with the different plan and they escaped.

what was the plan ?