The ratio of Reggie's age to Valen's age is 4 : 1. Next year, their average age will be 21. How old will Reggie be in 9 years' time?
| |
Reggie |
Valen |
Total |
| Before |
4 u |
1 u |
40 |
| Change |
+ 1 |
+ 1 |
|
| After |
4 u + 1 |
1 u + 1 |
42 |
Total age of Reggie and Valen this year
= 4 u + 1 u
= 5 u
Total age of Reggie and Valen this year
= 2 x 21 - 1 - 1
= 42 - 2
= 40
5 u = 40
1 u = 40 ÷ 5 = 8
Reggie's age in 9 years' time
= 4 u + 9
= 4 x 8 + 9
= 32 + 9
= 41
Answer(s): 41
