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

I have holes on the top and bottom. I have holes on my left and on my right. And I have holes in the middle, yet I still hold water. What am I?

An express train takes 3 seconds to enter the tunnel which is 1 km long.
If it is travelling at 120 km an hour, how long will it take to pass completely through the tunnel?

What is the coolest letter in the alphabet?

What does the following represent?

N N N N N N N

A A A A A A A

C C C C C C C

Why is it very easy to weigh a fish?

Two girls were born to the same mother, on the same day, at the same time, in the same month and year and yet they're not twins. How can this be ?

If you’ve got me, you want to share me; if you share me, you haven’t kept me. What am I?

Place the numbers from 1 to 9 in the circles in a manner that each side of the triangle sums up to 17.

How many times in a given day, minutes and hour clock comes in a straight line ?