What is the fewest number of coins that would be required in order to make sure each and every coin touches exactly three other coins?

I have teeth but i don't bite. Who Am I ?

A man was just doing his job when his suit was torn. Why did he die three minutes later?

If eleven plus two equals one, what does nine plus five equal?

Which Number is the odd one out?

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

You have 10 balls with you. A friend of yours out of nowhere asks you to place those ten balls in five lines such that each of the lines has exactly 4 balls on them. He needs to check your intelligence. Prove him by doing the task.

Next Number in the Series,

5, 16, 49, 104, ?

Below, you will find the mathematical proof that 10 equals 9.99999?. But is that possible or there is something wrong about it? Can you find the error?

x = 9.999999...
10x = 99.999999...
10x - x = 90
9x = 90
x = 10

It comprises roots which nobody sees,
Much taller than those trees,
Up and up it goes,
Still it never grows?

A man has to get a fox, a chicken, and a sack of corn across a river.

He has a rowboat, and it can only carry him and one other thing.
If the fox and the chicken are left together, the fox will eat the chicken.
If the chicken and the corn are left together, the chicken will eat the corn.

How does the man do it?