Replace the question mark with the correct number in below Picture:

What goes up but never comes down?

John left on a horse on Thursday , was gone for two days, and came back on Thursday after completing his work. How did that happen?

Look at the picture and find out which square is not linked with any of the other squares.

What's the only room from which no one can enter or leave

How many times can you subtract the number 5 from 25?

You are given 2 eggs.
You have access to a 100-storey building.
Eggs can be very hard or very fragile means it may break if dropped from the first floor or may not even break if dropped from 100th floor, Both eggs are identical.
You need to figure out the highest floor of a 100-storey building an egg can be dropped without breaking.
Now the question is how many drops you need to make. You are allowed to break 2 eggs in the process

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!!!

Why do you find that most of the buildings are deprived of the 13th floor?

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?