Archie's age is
35 his sister's age now. 15 years ago, his age was
25 that of his sister's. How old is Archie now?
| |
Archie |
Archie's sister |
Difference |
| Before |
2x2 =
4 u |
5x2 =
10 u |
3x2 =
6 u |
| Change |
+ 15 |
+ 15 |
|
| After |
3x3 =
9 u |
5x3 =
15 u |
2x3 =
6 u |
The difference in the age between Archie and Archie's sister remains unchanged. Make the difference in age the same. LCM of 3 and 2 is 6.
Increase in the age of Archie
= 9 u - 4 u
= 5 u
5 u = 15
1 u = 15 ÷ 5 = 3
Archie's age now
= 9 u
= 9 x 3
= 27
Answer(s): 27
