What do you get if you add 2 to 100 four times?

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?

Two natural numbers have a sum of less than 100 and are greater than one.

John knows the product of the numbers and Jacob knows the sum of numbers.

The following conversation takes place between them:
John: 'I am not aware of those numbers.'
Jacob: 'I knew you wouldn't be. I am not aware myself.'
John: 'Now I know them!'
Jacob: 'Now I know them, too!'

What are the two numbers?

If two fifty-foot ropes are suspended from a forty-foot ceiling that is twenty feet apart, how much rope will you be able to steal if you have a knife?

In the given picture, in how many ways can you read the word "Tiger"?

Find the missing number in the image below.

Can you find the hidden animal in the picture below?

Replace the question mark with the correct number in below Picture:

I have eight fingers and two thumbs but I do not live. What Am I?

What's the next in the series?

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