Mr Tommy is 2 times as old as his cousin, Justin. 10 years ago, the ratio in the age of Mr Tommy and Justin was 8 : 3. Find Justin's current age.
| |
Mr Tommy |
Justin |
Difference |
| Before |
8x1 =
8 u |
3x1 =
3 u |
5x1 =
5 u |
| Change |
+ 10 |
+ 10 |
|
| After |
2x5 =
10 u |
1x5 =
5 u |
1x5 =
5 u |
The difference in the age of Mr Tommy and Justin at first and in the end remains unchanged. Make the difference in age the same. LCM of 5 and 1 is 5.
The increase in the age of Mr Tommy and Justin is the same.
Increase in Justin's age
= 5 u - 3 u
= 2 u
2 u = 10
1 u = 10 ÷ 2 = 5
Justin's current age
= 5 u
= 5 x 5
= 25
Answer(s): 25
