The ratio of Liam's age to Justin's age is 4 : 3. Next year, their average age will be 15. How old will Liam be in 2 years' time?
|
Liam |
Justin |
Total |
Before |
4 u |
3 u |
28 |
Change |
+ 1 |
+ 1 |
|
After |
4 u + 1 |
3 u + 1 |
30 |
Total age of Liam and Justin this year
= 4 u + 3 u
= 7 u
Total age of Liam and Justin this year
= 2 x 15 - 1 - 1
= 30 - 2
= 28
7 u = 28
1 u = 28 ÷ 7 = 4
Liam's age in 2 years' time
= 4 u + 2
= 4 x 4 + 2
= 16 + 2
= 18
Answer(s): 18