Can you replace the question mark with the correct number?

What is the riddle which can be asked all day with a different correct answer each time.

What is the word or phrase?

Complete the table series riddle by finding the number that can replace "??".

Transform the word THINK into BRAIN while changing only one letter at a time in a manner that each of the word in the process is a real word!!!

Paul's height is six feet, he's an assistant at a butcher's shop and wears size 9 shoes. What does he weigh?

If six children and two dogs were under an umbrella, how come none of them got wet?

The average age of 10 members of a committee is the same as it was 4 years ago, because an old member has been replaced by a young member. Find how much younger is the new member ?

A 52% bias toss for head using the 51% tail bias coin was done to obtain a fair result.

Can you find how bias is the floor in this case?

John replied, when asked how old he was. In 2 years he will be twice as old as he was five years ago.' How old is he ?