The ratio of Tom's age to Zane's age is 9 : 5. Next year, their average age will be 15. How old will Tom be in 11 years' time?
| |
Tom |
Zane |
Total |
| Before |
9 u |
5 u |
28 |
| Change |
+ 1 |
+ 1 |
|
| After |
9 u + 1 |
5 u + 1 |
30 |
Total age of Tom and Zane this year
= 9 u + 5 u
= 14 u
Total age of Tom and Zane this year
= 2 x 15 - 1 - 1
= 30 - 2
= 28
14 u = 28
1 u = 28 ÷ 14 = 2
Tom's age in 11 years' time
= 9 u + 11
= 9 x 2 + 11
= 18 + 11
= 29
Answer(s): 29
