I am the beginning of the end, and the end of time and space. I am essential to creation, and I surround every place. What am I?

Three fair coins are tossed in the air and they land with heads up. Can you calculate the chances that when they are tossed again, two coins will again land with heads up?

There are six people in a family namely M, N, O, P, Q and R.

R and O are brother and sister.

N is the brother of Q's husband.
P is the father of M and grandfather of R.

How many male members are in the family?

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?

What has a ring but no finger?

Nine marbles are arranged in the image below. Can you slide two marbles to form a square?

An evil man kidnapped someone and made them take one of two pills. One was harmless, but the other was poisonous. Whichever pill the victim took, the kidnapper took the other one. The victim took their pill with water and died. The kidnapper survived. How did the kidnapper get the harmless pill?

I am a prime number.
The double of myself is equal to the square of me.

which number am I?

What has 88 keys?

What mathematical symbol can be put between 5 and 9, to get a number bigger than 5 and smaller than 9?