Question

Charles is

15 years older than his sister Barbara. In
12 years, he will be twice as old as Barbara. How old is each of them now?

Answer 1

Charles = 18

Barbara = 3

Explanation:

Currently

Charles: x+15

Barbara: x

In twelve years

Charles: x+27

Barbara: x+12

Equation - Charles's age in twelve years will be double Barbara's age in twelve years. Using the information about, create the equation

x+27=2(x+12)

x+27=2x+24

x=3