The ratio of Sean's age to Oliver's age is 7 : 4. Next year, their average age will be 23. How old will Sean be in 11 years' time?
|
Sean |
Oliver |
Total |
Before |
7 u |
4 u |
44 |
Change |
+ 1 |
+ 1 |
|
After |
7 u + 1 |
4 u + 1 |
46 |
Total age of Sean and Oliver this year
= 7 u + 4 u
= 11 u
Total age of Sean and Oliver this year
= 2 x 23 - 1 - 1
= 46 - 2
= 44
11 u = 44
1 u = 44 ÷ 11 = 4
Sean's age in 11 years' time
= 7 u + 11
= 7 x 4 + 11
= 28 + 11
= 39
Answer(s): 39