There are 20 people in an empty, square room. Each person has full sight of the entire room and everyone in it without turning his head or body, or moving in any way (other than the eyes). Where can you place an apple so that all but one person can see it?

Can you make four (4) nines (9) equal 100?

There are are five things wrong with this sentence; only geniuses will be able to to spot all of the mitstakes

Find three numbers such that When we multiply three numbers, we will get the prime numbers. The difference between the second and the first number is equal to the third and second.

A brand new Mobile Phone was on sale at 20% as a promotional offer. By what per cent must the Mobile price be increased to sell it at the original price again?

I’m tall when I’m young, and I’m short when I’m old. What am I?

A Scientist was fifty years old in the year 2000 but he was forty years old in the year 2010. How can this be possible?

PS: It has a logical answer.

Can you find the next number in the below sequence
3 , 7 , 10 , 11 , 12 , 17 ?

What Adam and Eve do not have but the rest of the people have?

If eleven plus two equals one, what does nine plus five equal?