The ratio of Brandon's age to Cole's age is 6 : 5. Next year, their average age will be 12. How old will Brandon be in 9 years' time?
| |
Brandon |
Cole |
Total |
| Before |
6 u |
5 u |
22 |
| Change |
+ 1 |
+ 1 |
|
| After |
6 u + 1 |
5 u + 1 |
24 |
Total age of Brandon and Cole this year
= 6 u + 5 u
= 11 u
Total age of Brandon and Cole this year
= 2 x 12 - 1 - 1
= 24 - 2
= 22
11 u = 22
1 u = 22 ÷ 11 = 2
Brandon's age in 9 years' time
= 6 u + 9
= 6 x 2 + 9
= 12 + 9
= 21
Answer(s): 21
