Can you find out the missing number in the grid?

What is full of holes but still holds water?

Who has married many women but was never married?

I am the fastest animal but cannot climb the tree. What am I?

Can you find the mistake in the below statement?

John was gifted a new Hayabusa. He drove x miles at 55mph. Then he drove x+20 miles at 40mps. He drove his bike for 100 minutes. How much distance did he travel?

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

A man always keeps a spare tyre in his car. To make full use of all the five tyres, he changes the tyres in a manner that for a distance of 1, 00,000 km, each of them runs the same distance.

Can you calculate the distance travelled by each tyre on that journey?

I am a three digit number.
My tens digit is five more than my ones digit.
My hundreds digit is eight less than my tens digit.
What number am I?

What is the centre of gravity?