A store owner had the same number of mangosteens, grapefruits and starfruits at first. After 52 starfruits, some mangosteens and grapefruits were removed, there were 141 fruits left. There were four times as many mangosteens as grapefruits left. The number of starfruits left was 12 less than the number of mangosteens. How many grapefruits were removed?
| |
Mangosteens |
Grapefruits |
Starfruits |
Total |
| Before |
1 |
1 |
1 |
|
| Change |
- ? |
- ? |
- 52 |
|
| After |
4 u |
1 u |
4 u - 12 |
141 |
Total number of fruits in the end
= 4 u + 1 u + 4 u - 12
= 9 u - 12
9 u - 12 = 141
9 u = 141 + 12
9 u = 153
1 u = 153 ÷ 9 = 17
Number of starfruits at first
= 4 u - 12 + 52
= 4 x 17 - 12 + 52
= 68 - 12 + 52
= 108
The number of grapefruits and starfruits at first was the same.
Number of grapefruits removed
= 108 - 1 u
= 108 - 17
= 91
Answer(s): 91
