Joan is 15 years older than her brother Bill.Eight years from now,Joan will be twice as old as Bill.How old is each at this time?

Question

Joan is 15 years older than her brother Bill.Eight years from now,Joan will be twice as old as Bill.How old is each at this time?

Answer 1

J = B + 15

J + 8 = 2(B+8)

Substitute B+15 for J in the second equation and solve for B. Insert that value into the first equation to solve for J. Check by putting both values into the second equation.