Question

Bruce is 4 times as old as Indy. 6 years ago, Bruce was 6 times as old as Indy. how old is bruce now?

Answer 1

4i = b
6(i-6) = b-6

6(i-6) = 4i - 6
6i - 36 = 4i - 6
2i - 36 = -6
2i = 30
i = 15 years old
b = 60 years old

Check:
15 * 4 = 60
9 * 6 = 54 :)