Find the value of "?" in the ball picture Riddle below:

Be active and find the killer in the picture Riddle below.

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?

Three friends named Mr. Black, Mr. Yellow and Mr. Green enter a pub on a weekend night. They are wearing either a Black, Yellow or Green shirt.

Mr. Yellow says to them, 'Did you notice that we all are wearing different color shirts than our names?'

To this, the man who was wearing the Green shirt said. 'Wow, thats right.'

Can you identify who is wearing which colour shirt ?

I am a prime number.
The double of myself is equal to the square of me.

which number am I?

Things are just as they seem, right? Well, check again.
Can you count the number of tigers in this picture ?

What part of Turkey has the most feathers?

Accidentally, two trains are running in the opposite direction and enter a tunnel that is 200 miles long. A supersonic bird that has fled the lab and taken shelter in the tunnel starts flying from one train towards the other at a speed of 1000 mph. As soon as it reaches the second train, he starts flying back to avoid collision and meets the first train again at the other end. The bird keeps flying to and fro till the trains collide with each other.

What is the total distance that the supersonic bird has traveled till the trains collided?

What has six faces, but does not wear makeup, has twenty-one eyes, but cannot see? What is it?

What comes
Once in a Year
Twice in a Month
4 times in a Week
6 times in a Day