How many pluses should we put between the digits of 987654321 to get a total of 99, and where?

Which is faster, Heat or Cold ? Explain.

Find the next number in the series

12, 20, 40, 72, 116, 172 ?

I was born in a small house and I live in it all alone. No windows and no doors have been assigned to my house. The only way I can go out is by breaking through the walls of my house.

Who am I?

I have two coins.
* One of the coins is a faulty coin having a tail on both sides of it.
* The other coin is a perfect coin (heads on side and tail on other).

I blindfold myself and pick a coin and put the coin on the table. The face of the coin towards the sky is the tail.

What is the probability that another side is also tail?

If,

A + B = C
D - C = A
E - B = C

Based on the above equations, find out the answer for:

D + F = ?

John was piloting a plane behind a car but was never able to overtake it. Why?

We know that the number 7 is the prime followed by a cube. Which next number is also a prime followed by a cube?

I have lakes with no water, mountains with no stone and cities with no buildings. What am I?

What shoe company does this rebus represent?