The ratio of Perry's age to Jack's age is 3 : 1. Next year, their average age will be 13. How old will Perry be in 5 years' time?
|
Perry |
Jack |
Total |
Before |
3 u |
1 u |
24 |
Change |
+ 1 |
+ 1 |
|
After |
3 u + 1 |
1 u + 1 |
26 |
Total age of Perry and Jack this year
= 3 u + 1 u
= 4 u
Total age of Perry and Jack this year
= 2 x 13 - 1 - 1
= 26 - 2
= 24
4 u = 24
1 u = 24 ÷ 4 = 6
Perry's age in 5 years' time
= 3 u + 5
= 3 x 6 + 5
= 18 + 5
= 23
Answer(s): 23