Can you place six X (crosses) in below board without making three in a row in any way ?

using four eights (8) and a one (1) and one mathematical symbol , create the number 100

All of Jacob's shoes are red except two.
All of Jacob's shoes are green except two.
All of Jacob's shoes are yellow except two.

How many shoes does Jacob have?

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

I look at you, you look at me, I raise my right, you raise your left. What am I?

The centre of the third figure is empty. What digit should fit inside?

I speak without a mouth, and hear without ears. I have no-body, but I come alive with the wind. What am I?

Two friends were stuck in a cottage. They had nothing to do and thus they started playing cards. Suddenly the power went off and Friend 1 inverted the position of 15 cards in the normal deck of 52 cards and shuffled it. Now he asked Friend 2 to divide the cards into two piles (need not be equal) with equal number of cards facing up. The room was quite dark and Friend 2 could not see the cards. He thinks for a while and then divides the cards in two piles.

On checking, the count of cards facing up is same in both the piles. How could Friend 2 have done it ?

A professor thinks of two consecutive numbers between 1 and 10.
'A' knows the 1st number and 'B' knows the second number

A: I do not know your number.
B: Nor do I know your number.
A: Now I know.

What are the four solutions for this?

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