10+10 and 11+11 can give you the same answer.

Explain how?

How can you throw a ball as hard as you can and have it come back to you even if it doesn't hit anything there is nothing attached to it and no one else catches or throws it.

A man is shown a portrait painting. He looks closely, then tells, “Brothers and sisters have I none, but that man’s father is my father’s son!” Who is the man in the portrait?

What does this rebus means ?

PROG WORKRESS

John’s parents have three sons: Snap, Crackle, and what’s the name of the third son?

I have thought of a number that is made up by using all the ten digits just once. Here are a few clues for you to guess my number:

First digits is divisible by 1.
First two digits are divisible by 2.
First three digits are divisible by 3.
First four digits are divisible by 4.
First five digits are divisible by 5.
First six digits are divisible by 6.
First seven digits are divisible by 7.
First eight digits are divisible by 8.
First nine digits are divisible by 9.
The number is divisible by 10.

Can you find out the number ?

How many pluses should we put between the digits of 987654321 to get a total of 99, and where?

The following "Brain Bat" means Slow Down.
S
L
O
W

Using the same logic, can you tell us what does the following Brain Bat means ?
E
V
I
G

I have a hole in my back and legs I lack.
I live where I can’t breathe and I eat without teeth.
What am I?

Count the number of triangles in the picture below: