A store owner had the same number of pomegranates, grapefruits and dragonfruits at first. After 105 dragonfruits, some pomegranates and grapefruits were used, there were 178 fruits left. There were twice as many pomegranates as grapefruits left. The number of dragonfruits left was 12 fewer than the number of pomegranates. How many grapefruits were used?
| |
Pomegranates |
Grapefruits |
Dragonfruits |
Total |
| Before |
1 |
1 |
1 |
|
| Change |
- ? |
- ? |
- 105 |
|
| After |
2 u |
1 u |
2 u - 12 |
178 |
Total number of fruits in the end
= 2 u + 1 u + 2 u - 12
= 5 u - 12
5 u - 12 = 178
5 u = 178 + 12
5 u = 190
1 u = 190 ÷ 5 = 38
Number of dragonfruits at first
= 2 u - 12 + 105
= 2 x 38 - 12 + 105
= 76 - 12 + 105
= 169
The number of grapefruits and dragonfruits at first was the same.
Number of grapefruits used
= 169 - 1 u
= 169 - 38
= 131
Answer(s): 131
