What is so fragile that saying its name breaks it?

Sherlock Holmes was challenged to make a pre-drawn line smaller without erasing it. He did it in fractions of seconds. How?

Which Number is the odd one out?

A) 7145
B) 2716
C) 5321
D) 4135

I look at you, you look at me, I raise my right, you raise your left. 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.

How can you drop a raw egg from a height onto a concrete floor without cracking it?

How do you go from 98 to 720 using just one letter?

You see a boat filled with people, yet there isn’t a single person on board. How is that possible?

It has five wheels, though often think four, You cannot use it without that one more, You can put things in it, you can strap things on top, You can't find it in the market, but you can still go shop. What is it?

A man has eighty-one cows ( numbered 1,2,3...81 as such). The beauty is that cow no. 1 gives 1ltr of milk, cow no. 2 gives 2ltrs of milk and so on. The man wants to equally distribute the cows among his nine sons so that each one of them gets the same quantity of milk.