If 21x = 79x, what is the value of x?

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?

P is the father of Q and S is the son of R. T is the brother of P and has a daughter U. If R is the sister of P, then what is the relation between U, Q and S?

A number can be multiplied by multiple of nine
i.e 9 18 27 36 45 ...

and the resulting number consist of only one digit.

Can you identify the number ?

Can you solve the below algebraic mathematical equation?

(J+O+I+N+T)3 = JOINT

In a fruit store, there was a unique weighing machine that was made to weigh only cherries and strawberries as they were priced the same.

Other fruits like watermelons or mango had different machines as they were expensive.

A man successfully buys watermelons at the price of cherries. How?

what's the probability of getting a king or a queen from a pack of 52 cards?

1. What does:
TIM JOB
represent?

2. What does:
MO_ _
represent?

In a chess board, the queen piece can move horizontally, vertically and diagonally freely. The picture represents the same.Can you place 8 queens on the board in a manner that none of the queens can attack each other?

I come in different shapes and sizes.
Parts of me are curved, other parts are straight.
You can put me anywhere you like,
but there is only one right place for me.
What am I?