This puzzle is for Harry Potter fans. Do you know why Tom Riddle is called Lord Voldemort?

Luis Garavito killed Density x Volume.

Who is Luis Garavito ?

There are a number of books on a shelf. If one book is the 4th from the left and 6th from the right, how many books are on the shelf?

Can you identify the hidden rebus in the image below?

It's pretty hard to give up.
If you remove a part of it, you will be left with a bit.
Even if you remove another part, the bit still remains.
Remove one more and it still remains.

What is it?

what's the probability of getting a king or a queen from a pack of 52 cards?

What's the next in the series?

H, Be, F, S, Mn, Kr, In, Gd, Tl, ?

A famous swimmer can swim downstream in a lake in exactly 40 minutes with the lake current.
He can swim upstream in that lake in exactly 60 minutes against the lake current.
The length of the lake is 2 km.

How long he can cover the distance of one side at a still lake with no current?

It walks on 4 when its young, walks on 2 when it's older, and walks on 3 when its very old?

An ape is trying to climb on a pole that is 60 feet high. Due to the slippery surface, the ape climbs 3 feet in a minute only to slip back 2 feet.

How much time do you think the monkey will take to reach the top of the pole?