Take 9 from 6, 10 from 9, 50 from 40, and leave 6.

How Come ??

What does does this rebus picture means ?

A large water tank has two inlet pipes (a large one and a small one) and one outlet pipe. It takes 3 hours to fill the tank with the large inlet pipe. On the other hand, it takes 6 hours to fill the tank with the small inlet pipe. The outlet pipe allows the full tank to be emptied in 9 hours.

What fraction of the tank (initially empty) will be filled in 0.64 hours if all three pipes are in operation? Give your answer to two decimal places (e.g., 0.25, 0.5, or 0.75).

Move four matchsticks to the below square to form three squares?

What happened when the wheel was invented?

Our product and our sum always give the same answer. Who are we?

If in a car race, the man who came two places in front of the last man finished one ahead of the man who came fifth, how many contestants were there?

Can you convert the number zero(0) into a positive number using just one mathematical operator ?

Until it is measured, not known. Yet how you miss it when it has gone. What is it?

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?