Mr Jeremy is 3 times as old as his cousin, Zeph. 9 years ago, the ratio in the age of Mr Jeremy and Zeph was 9 : 2. Find Zeph's current age.
|
Mr Jeremy |
Zeph |
Difference |
Before |
9x2 = 18 u |
2x2 = 4 u |
7x2 = 14 u |
Change |
+ 9 |
+ 9 |
|
After |
3x7 = 21 u |
1x7 = 7 u |
2x7 = 14 u |
The difference in the age of Mr Jeremy and Zeph 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 Jeremy and Zeph is the same.
Increase in Zeph's age
= 7 u - 4 u
= 3 u
3 u = 9
1 u = 9 ÷ 3 = 3
Zeph's current age
= 7 u
= 7 x 3
= 21
Answer(s): 21