The ratio of Brandon's age to Pierre's age is 9 : 5. Last year, their average age was 20. How old will Pierre be in 8 years' time?
| |
Brandon |
Pierre |
Total |
| Before |
9 u - 1 |
5 u - 1 |
40 |
| Change |
+ 1 |
+ 1 |
|
| After |
9 u |
5 u |
42 |
Total age of Brandon and Pierre this year
= 9 u + 5 u
= 14 u
Total age of Brandon and Pierre this year
= 2 x 20 + 1 + 1
= 40 + 2
= 42
14 u = 42
1 u = 42 ÷ 14 = 3
Pierre's age in 8 years' time
= 5 u + 8
= 5 x 3 + 8
= 15 + 8
= 23
Answer(s): 23
