What does this rebus puzzle means ?

Prove that twice of ten is the same as twice of eleven.

Replace the question mark with the correct number below.

A certain street contains 100 buildings. They are numbered from 1 to 100. How many 9's are used in these numbers?

When monkey rotate the gear, which mark will be hit 1 or 2 ?

what's the probability of getting a king or a queen from a pack of 52 cards?

John has played 50 ODI's and his average is 50. How many runs should he score in his 51st ODI, so that his average score jumps to 51?

A man who was outside in the rain without an umbrella or hat didn’t get a single hair on his head wet. Why?

By removing one matchstick and adding one matchstick, can you convert the word "ZOO" to an animal name?

Four children having five rocks each were playing a game in which they had to throw the rock at a particular solid area in the water. Child 1- Succeeded in throwing three rocks at a solid area but one of the rocks sunk. Child 3 - His aim was so bad that all rocks got sunk. Child 4- He was awesome and none of the rocks got sunk. Child 2 - Was the winner but was struck by a rock in the head and died. Who killed Child 2?