The ratio of Ben's age to Seth's age is 2 : 1. Last year, their average age was 11. How old will Seth be in 10 years' time?
| |
Ben |
Seth |
Total |
| Before |
2 u - 1 |
1 u - 1 |
22 |
| Change |
+ 1 |
+ 1 |
|
| After |
2 u |
1 u |
24 |
Total age of Ben and Seth this year
= 2 u + 1 u
= 3 u
Total age of Ben and Seth this year
= 2 x 11 + 1 + 1
= 22 + 2
= 24
3 u = 24
1 u = 24 ÷ 3 = 8
Seth's age in 10 years' time
= 1 u + 10
= 1 x 8 + 10
= 8 + 10
= 18
Answer(s): 18
