My grandad is 88 years old. How old am i now, if seven years ago my granddad was 9 times my age?

Question

The answer is 16, but i think that the answer is wrong. Please, could you help me with the question

Answer 1

Let x be your current age; your grandad is currently 88.  Seven years ago you were x-7 years old and your grandad was 88-7 = 81 years old and was nine times older than you:

 

81 = 9(x-7)

9 = x - 7

 

Solve for x.