The ratio of Oscar's age to Jeremy's age is 8 : 3. Last year, their average age was 10. How old will Jeremy be in 9 years' time?
| |
Oscar |
Jeremy |
Total |
| Before |
8 u - 1 |
3 u - 1 |
20 |
| Change |
+ 1 |
+ 1 |
|
| After |
8 u |
3 u |
22 |
Total age of Oscar and Jeremy this year
= 8 u + 3 u
= 11 u
Total age of Oscar and Jeremy this year
= 2 x 10 + 1 + 1
= 20 + 2
= 22
11 u = 22
1 u = 22 ÷ 11 = 2
Jeremy's age in 9 years' time
= 3 u + 9
= 3 x 2 + 9
= 6 + 9
= 15
Answer(s): 15
