The ratio of Simon's age to Riordan's age is 9 : 1. Last year, their average age was 24. How old will Riordan be in 4 years' time?
| |
Simon |
Riordan |
Total |
| Before |
9 u - 1 |
1 u - 1 |
48 |
| Change |
+ 1 |
+ 1 |
|
| After |
9 u |
1 u |
50 |
Total age of Simon and Riordan this year
= 9 u + 1 u
= 10 u
Total age of Simon and Riordan this year
= 2 x 24 + 1 + 1
= 48 + 2
= 50
10 u = 50
1 u = 50 ÷ 10 = 5
Riordan's age in 4 years' time
= 1 u + 4
= 1 x 5 + 4
= 5 + 4
= 9
Answer(s): 9
