Mr Will is 2 times as old as his cousin, Charlie. 30 years ago, the ratio in the age of Mr Will and Charlie was 9 : 2. Find Charlie's current age.
| |
Mr Will |
Charlie |
Difference |
| Before |
9x1 =
9 u |
2x1 =
2 u |
7x1 =
7 u |
| Change |
+ 30 |
+ 30 |
|
| After |
2x7 =
14 u |
1x7 =
7 u |
1x7 =
7 u |
The difference in the age of Mr Will and Charlie at first and in the end remains unchanged. Make the difference in age the same. LCM of 7 and 1 is 7.
The increase in the age of Mr Will and Charlie is the same.
Increase in Charlie's age
= 7 u - 2 u
= 5 u
5 u = 30
1 u = 30 ÷ 5 = 6
Charlie's current age
= 7 u
= 7 x 6
= 42
Answer(s): 42
