A doctor and a boy were fishing. The boy was the doctor’s son, but the doctor was not the boy’s father. Who was the doctor?

1 + 9 + 8 = ?
considering, 28 + 8 + 92 = 10

Baseball bat and ball cost $100. If the bat cost $99 more than the ball, what is the cost of each?

Can you find out which number multiplied by itself will give the output as 12345678987654321?

Can you count the number of seconds in a year?

Clue: You need to bother about calculation.

Sherlock Holmes was challenged to make a pre-drawn line smaller without erasing it. He did it in fractions of seconds. How?

You stand in front of two doors. A guard stands next to each door. You know the following things: one path leads to paradise, the other leads to death. You cannot distinguish between the two doors. You also know that one of the two guards always tells the truth and the other always lies. You have permission to ask one guard one question to discover which door leads to paradise. What one question would you ask to guarantee you enter the door to paradise?

A rubber ball keeps on bouncing back to 2/3 of the height from which it is dropped. Can you calculate the fraction of its original height that the ball will bounce after it is dropped and it has bounced four times without any hindrance ?

Which tank will fill first?

If we add four times the age of John four years from now to five times his age five years from now we get ten times his current age.

How old will John be two years from now?