The ratio of Fred's age to Ian's age is 3 : 1. Last year, their average age was 13. How old will Ian be in 5 years' time?
| |
Fred |
Ian |
Total |
| Before |
3 u - 1 |
1 u - 1 |
26 |
| Change |
+ 1 |
+ 1 |
|
| After |
3 u |
1 u |
28 |
Total age of Fred and Ian this year
= 3 u + 1 u
= 4 u
Total age of Fred and Ian this year
= 2 x 13 + 1 + 1
= 26 + 2
= 28
4 u = 28
1 u = 28 ÷ 4 = 7
Ian's age in 5 years' time
= 1 u + 5
= 1 x 7 + 5
= 7 + 5
= 12
Answer(s): 12
