The ratio of Caden's age to Ryan's age is 7 : 1. Next year, their average age will be 21. How old will Caden be in 12 years' time?
| |
Caden |
Ryan |
Total |
| Before |
7 u |
1 u |
40 |
| Change |
+ 1 |
+ 1 |
|
| After |
7 u + 1 |
1 u + 1 |
42 |
Total age of Caden and Ryan this year
= 7 u + 1 u
= 8 u
Total age of Caden and Ryan this year
= 2 x 21 - 1 - 1
= 42 - 2
= 40
8 u = 40
1 u = 40 ÷ 8 = 5
Caden's age in 12 years' time
= 7 u + 12
= 7 x 5 + 12
= 35 + 12
= 47
Answer(s): 47
