The ratio of Tommy's age to Ahmad's age is 3 : 1. Next year, their average age will be 11. How old will Tommy be in 9 years' time?
|
Tommy |
Ahmad |
Total |
Before |
3 u |
1 u |
20 |
Change |
+ 1 |
+ 1 |
|
After |
3 u + 1 |
1 u + 1 |
22 |
Total age of Tommy and Ahmad this year
= 3 u + 1 u
= 4 u
Total age of Tommy and Ahmad this year
= 2 x 11 - 1 - 1
= 22 - 2
= 20
4 u = 20
1 u = 20 ÷ 4 = 5
Tommy's age in 9 years' time
= 3 u + 9
= 3 x 5 + 9
= 15 + 9
= 24
Answer(s): 24