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

Andrew’s doctor gives him three pills and tells him to take one every half hour. How much time will have passed by the time Andrew’s taken all three pills?

What is the fastest way to double your money?

Double it and multiply it by 4. Then divide it by 8 and you’ll have it once more. What number is it?

What has many keys but can’t open a single lock?

Akbar called Birbal and asked him to draw a line on the floor. He asked Birbal to make that line smaller without erasing it. Birbal smiled and did it before Akbar could blink his eyes.

How did he managed to do it?

A boy and a girl are sitting on the porch.
"I'm a boy," says the child with black hair.
"I'm a girl," says the child with red hair.
If at least one of them is lying, who is which?

A 3 digit number is such that it's unit digit is equal to the product of the other two digits which are prime. Also, the difference between it's reverse and itself is 396.

What is the sum of the three digits?

What is the difference between a jeweller and a jailer?

One is to three as three is to five and five is to four and four is the magic number.
What is the pattern?