The ratio of Sean's age to Perry's age is 2 : 1. Next year, their average age will be 16. How old will Sean be in 9 years' time?
| |
Sean |
Perry |
Total |
| Before |
2 u |
1 u |
30 |
| Change |
+ 1 |
+ 1 |
|
| After |
2 u + 1 |
1 u + 1 |
32 |
Total age of Sean and Perry this year
= 2 u + 1 u
= 3 u
Total age of Sean and Perry this year
= 2 x 16 - 1 - 1
= 32 - 2
= 30
3 u = 30
1 u = 30 ÷ 3 = 10
Sean's age in 9 years' time
= 2 u + 9
= 2 x 10 + 9
= 20 + 9
= 29
Answer(s): 29
