The ratio of Valen's age to Fred's age is 3 : 1. Last year, their average age was 15. How old will Fred be in 3 years' time?
| |
Valen |
Fred |
Total |
| Before |
3 u - 1 |
1 u - 1 |
30 |
| Change |
+ 1 |
+ 1 |
|
| After |
3 u |
1 u |
32 |
Total age of Valen and Fred this year
= 3 u + 1 u
= 4 u
Total age of Valen and Fred this year
= 2 x 15 + 1 + 1
= 30 + 2
= 32
4 u = 32
1 u = 32 ÷ 4 = 8
Fred's age in 3 years' time
= 1 u + 3
= 1 x 8 + 3
= 8 + 3
= 11
Answer(s): 11
