The ratio of Ahmad's age to Jeremy's age is 9 : 5. Next year, their average age will be 15. How old will Ahmad be in 12 years' time?
| |
Ahmad |
Jeremy |
Total |
| Before |
9 u |
5 u |
28 |
| Change |
+ 1 |
+ 1 |
|
| After |
9 u + 1 |
5 u + 1 |
30 |
Total age of Ahmad and Jeremy this year
= 9 u + 5 u
= 14 u
Total age of Ahmad and Jeremy this year
= 2 x 15 - 1 - 1
= 30 - 2
= 28
14 u = 28
1 u = 28 ÷ 14 = 2
Ahmad's age in 12 years' time
= 9 u + 12
= 9 x 2 + 12
= 18 + 12
= 30
Answer(s): 30
