Mr Bryan is 3 times as old as his son, Seth. 12 years ago, the ratio in the age of Mr Bryan and Seth was 9 : 2. Find Seth's current age.
| |
Mr Bryan |
Seth |
Difference |
| Before |
9x2 =
18 u |
2x2 =
4 u |
7x2 =
14 u |
| Change |
+ 12 |
+ 12 |
|
| After |
3x7 =
21 u |
1x7 =
7 u |
2x7 =
14 u |
The difference in the age of Mr Bryan and Seth at first and in the end remains unchanged. Make the difference in age the same. LCM of 7 and 2 is 14.
The increase in the age of Mr Bryan and Seth is the same.
Increase in Seth's age
= 7 u - 4 u
= 3 u
3 u = 12
1 u = 12 ÷ 3 = 4
Seth's current age
= 7 u
= 7 x 4
= 28
Answer(s): 28
