The ratio of Pierre's age to Gabriel's age is 3 : 1. Last year, their average age was 17. How old will Gabriel be in 2 years' time?
|
Pierre |
Gabriel |
Total |
Before |
3 u - 1 |
1 u - 1 |
34 |
Change |
+ 1 |
+ 1 |
|
After |
3 u |
1 u |
36 |
Total age of Pierre and Gabriel this year
= 3 u + 1 u
= 4 u
Total age of Pierre and Gabriel this year
= 2 x 17 + 1 + 1
= 34 + 2
= 36
4 u = 36
1 u = 36 ÷ 4 = 9
Gabriel's age in 2 years' time
= 1 u + 2
= 1 x 9 + 2
= 9 + 2
= 11
Answer(s): 11