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

What has one eye, but can’t see?

When I got four, I have it none.
When I got two, I have it some.
When I got none, I have it all.

What is it?

What is the largest amount of money that you can possess in change and still if someone asks you for a dollar, you won't be able to give?

Can you find the key in the picture below?

After undergoing a successful eye operation, A blind girl has just boarded a train to her home. The doctor asked her to open the bandages after 3 hours. On her train journey, she opened the bandages and within a fraction of the time she commits suicide by jumping off the train.

Though her operation was successful, Why did she commit suicide?

Which three-digit number, made of consecutive digits, like 567, is 2 less than a cube and 2 more than a square?

The sum of a mother, her baby and her dog's weight is 170 Kg. How much does the baby weigh if the mother weighs 100 kg more than the combined weight of the baby and the dog, and the dog weighs 60 per cent less than the baby?

On a bright sunny day, two fathers took their son fishing in the lake. Each man and son were able to catch one fish. When they returned to their camp, there were only three fishes in the basket. What happened?

PS: None of the fish were eaten, lost, or thrown back.

You have two rectangular wires.

Both of them have property that when you light the fire from one end , it will take 60 minutes to get completely burn.

However, they do not burn at consistent speed (i.e it might be possible 1st 20% burn in 50 minutes and 80% can burn in 10 minutes).

So how could you measure 45 minutes ?