The ratio of Andy's age to Fred's age is 6 : 1. Next year, their average age will be 15. How old will Andy be in 9 years' time?
| |
Andy |
Fred |
Total |
| Before |
6 u |
1 u |
28 |
| Change |
+ 1 |
+ 1 |
|
| After |
6 u + 1 |
1 u + 1 |
30 |
Total age of Andy and Fred this year
= 6 u + 1 u
= 7 u
Total age of Andy and Fred this year
= 2 x 15 - 1 - 1
= 30 - 2
= 28
7 u = 28
1 u = 28 ÷ 7 = 4
Andy's age in 9 years' time
= 6 u + 9
= 6 x 4 + 9
= 24 + 9
= 33
Answer(s): 33
