A fruit stall had 3 times as many starfruits as mangosteens. After 15 mangosteens were sold, the number of starfruits became 12 times the number of the remaining mangosteens. How many mangosteens were there at the fruit stall at first?
| |
Starfruits |
Mangosteens |
| Before |
3x4 =
12 u |
1x4 =
4 u |
| Change |
|
- 15 |
| After |
12 u |
1 u |
The number of starfruits remains unchanged. Make the number of starfruits the same. LCM of 3 and 12 is 12.
Number of mangosteens in the end = 4 u - 15
4 u - 15 = 1 u
4 u - 1 u = 15
3 u = 15
1 u = 15 ÷ 3 = 5
Number of mangosteens at the fruit stall at first
= 4 u
= 4 x 5
= 20
Answer(s): 20
