Charlie bought some starfruits and persimmons in the ratio of 1 : 3 . After buying another 15 fruits each, the ratio becomes 5 : 12. Find the number of starfruits and persimmons he had at first.
| |
Starfruits |
Persimmons |
Difference |
| Before |
1x7 =
7 u |
3x7 =
21 u |
2x7 =
14 u |
| Change |
+ 15 |
+ 15 |
|
| After |
5x2 =
10 u |
12x2 =
24 u |
7x2 =
14 u |
Since the same number of fruits bought for each type of fruits is the same, the difference in the number of starfruits and persimmons at first and in the end remains unchanged.
Make the difference in the number of starfruits and persimmons the same. LCM of 2 and 7 is 14.
Increase in the number of starfruits
= 10 u - 7 u
= 3 u
3 u = 15
1 u = 15 ÷ 3 = 5
Number of persimmons and starfruits that Charlie had at first
= 7 u + 21 u
= 28 u
= 28 x 5
= 140
Answer(s): 140
