The sum of Billy's and his sister Diane ages is 37. If three years ago Billy was 11 years older than Diane, then what is the age of each of them right now?

Answer 1

11+d=b
b+3 +d=37

so..

plug in the top equation to the bottom and you get

d+11 +d=37

so 2d=26

divide and you get d=13 plug this into the top equation and you get

b=24

so

answer:
b=24
d=13

and you check by adding both and they equal 37