I am thinking of a number. Multiplying it by 7 and adding 2 is equal to multiplying it by 2 and adding 7. What is the number?

Answer: The number you are thinking is 1

Solution:

Let the number you are thinking be = x

Multiplying the number by 7 = 7x

Adding the number 2 = 7x + 2

Multiplying the number by 2 = 2x

Adding the number 7 = 2x + 7

Both these equation are equal to one another

7x + 2 = 2x + 7

Simplify the equation,

7x - 2x = 7 - 2

5x = 5

x = 1