The ratio of Bobby's age to Cole's age is 3 : 1. Next year, their average age will be 23. How old will Bobby be in 3 years' time?
| |
Bobby |
Cole |
Total |
| Before |
3 u |
1 u |
44 |
| Change |
+ 1 |
+ 1 |
|
| After |
3 u + 1 |
1 u + 1 |
46 |
Total age of Bobby and Cole this year
= 3 u + 1 u
= 4 u
Total age of Bobby and Cole this year
= 2 x 23 - 1 - 1
= 46 - 2
= 44
4 u = 44
1 u = 44 ÷ 4 = 11
Bobby's age in 3 years' time
= 3 u + 3
= 3 x 11 + 3
= 33 + 3
= 36
Answer(s): 36
