Zeph's age is
25 his sister's age now. In 30 years' time, his age will be
35 that of his sister's. How old is Zeph now?
|
Zeph |
Zeph's sister |
Difference |
Before |
2x2 = 4 u |
5x2 = 10 u |
3x2 = 6 u |
Change |
+ 30 |
+ 30 |
|
After |
3x3 = 9 u |
5x3 = 15 u |
2x3 = 6 u |
The difference in the age between Zeph and Zeph's sister remains unchanged. Make the difference in age the same. LCM of 3 and 2 is 6.
Increase in the age of Zeph
= 9 u - 4 u
= 5 u
5 u = 30
1 u = 30 ÷ 5 = 6
Zeph's age now
= 4 u
= 4 x 6
= 24
Answer(s): 24