Question

Sophie wrote a two-digit number on the board. Max wrote the digit 3 to the right of it and got a number that is bigger than the Sophie’s number by 372. What number did Sophie write on the board?

Answer 1

Sophie wrote 41 on the board

Explanation:

x = Sophie’s number

10x + 3 = Max's number

Let's solve for x, this way:

x + 372 = 10x + 3

x - 10x = 3 - 372 (Like terms)

-9x = -369

x = -369/-9

x = 41

10x + 3 = 41 * 10 + 3 = 413