How many triangles are there on the puzzle below?

13 decks of cards have been mixed. What is the minimum number of cards that must be taken out from the above-mixed cards to guarantee at least one 'four of a kind?

Who has married many women but was never married?

I never was there, I am always to be.
You have never ever seen me, not ever you will.
Yet I am the confidence of everyone.

Who Am I?

Can you count the number of squares in the given picture?

I am five letter word that is under you.
If you remove my 1st letter, then I am over you.
If you remove my 1st and 2nd letters then I am all around you.

Who am I?

I’m tall when I’m young, and I’m short when I’m old. What am I?

Cristina was born in 1888. She just had her 30th birthday today how did that happen?

Can you calculate the probability of getting a sum of six when a dice is thrown twice?

If,

6 / 7 = 2
3 / 9 = 7
8 / 2 = 6

Then

4 / 5 = ?