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

Can you think of a smallest +ve number such that if we shuffle the digits of the number, the new number becomes double the original number?

What does this mathematical rebus means ?

What will be the best approach to finding all the prime numbers less than 75 that leave an odd reminder when we divide them with 5?

Using mathematical symbols like +, -, and x in order to make the equations correct. Replace # with the above-given symbols.

9 # 8 # 7 # 6 # 5 # 4 = 91

Get total of 120 by using five zeros 0,0,0,0,0 and any one mathematical operator.
Do you ?

John can eat 27 chocolates in an hour, Jacob can eat 2 chocolates in 10 minutes, and Jolly can eat 7 chocolates in 20 minutes. How long will it take them to share and eat a box of 120 chocolates whilst playing Chess?

Can you find a seven digit number which describes itself. The first digit is the number of zeros in the number. The second digit is the number of ones in the number, etc. For example, in the number 21200, there are 2 zeros, 1 one, 2 twos, 0 threes and 0 fours.

Our product and our sum always give the same answer. Who are we?

A tree doubled in height each year until it reached its maximum height over the course of ten years. How many years did it take for the tree to reach half its maximum height?