The ratio of Luis's age to Pierre's age is 3 : 2. Next year, their average age will be 11. How old will Luis be in 6 years' time?
| |
Luis |
Pierre |
Total |
| Before |
3 u |
2 u |
20 |
| Change |
+ 1 |
+ 1 |
|
| After |
3 u + 1 |
2 u + 1 |
22 |
Total age of Luis and Pierre this year
= 3 u + 2 u
= 5 u
Total age of Luis and Pierre this year
= 2 x 11 - 1 - 1
= 22 - 2
= 20
5 u = 20
1 u = 20 ÷ 5 = 4
Luis's age in 6 years' time
= 3 u + 6
= 3 x 4 + 6
= 12 + 6
= 18
Answer(s): 18
