What number should come in place of the question mark below?

While going to your grandmother's house, you counted Twenty houses on the right side. While returning back to your home, you counted Twenty houses on the left side.

How many houses are there between your home and your grandmother's home?

John bought 150 chocolates but he misplaced some of them. His Father asked him how many chocolates were misplaced.
He gave the following answer to him:
If you count in pairs, one remains
If you count in threes, two remain
If you count in fours, three remain
If you count in fives, four remain
If you count in sixes, five remain
If you count in sevens, no chocolate remains.

Can you analyze the statements and tell us how many chocolates were lost?

Do you know of a place where the wind blows south and then suddenly shifts direction towards the north?

A Child was born in Lahore, Pakistan.

Still child is not a Pakistani citizen.why ?

My friends called me Iron59 because my parents are a chemist and a mathematician. What is my real name?

Count the number of lines in the image below ?

How many cubic feet of dirt are in a hole of one foot deep, three feet long, and two feet wide?

What is more useful when it is broken?

A man stands on one side of a river, his dog on the other. The man calls his dog, who immediately crosses the river without getting wet and without using a bridge or a boat. How did the dog do it?