The ratio of Luke's age to George's age is 8 : 1. Next year, their average age will be 10. How old will Luke be in 12 years' time?
|
Luke |
George |
Total |
Before |
8 u |
1 u |
18 |
Change |
+ 1 |
+ 1 |
|
After |
8 u + 1 |
1 u + 1 |
20 |
Total age of Luke and George this year
= 8 u + 1 u
= 9 u
Total age of Luke and George this year
= 2 x 10 - 1 - 1
= 20 - 2
= 18
9 u = 18
1 u = 18 ÷ 9 = 2
Luke's age in 12 years' time
= 8 u + 12
= 8 x 2 + 12
= 16 + 12
= 28
Answer(s): 28