Math problem about ages

Question

My age is 3 years less than 5 times my sister's age. If I am 27, what is the sum of my age and my sister's age?

Answer 1

Let M be your age and S be your sister's age:

M = 5S - 3 Substitute in your age of 27 for M and solve

27 = 5S -3

30 = 5S

6 = S

Your age is 27 and your sister's age is 6. Therefore, the sum of both ages is 33.