A fruit seller had the same number of dragonfruits, persimmons and kiwis at first. After 141 kiwis, some dragonfruits and persimmons were used, there were 109 fruits left. There were thrice as many dragonfruits as persimmons left. The number of kiwis left was 31 fewer than the number of dragonfruits. How many persimmons were used?
| |
Dragonfruits |
Persimmons |
Kiwis |
Total |
| Before |
1 |
1 |
1 |
|
| Change |
- ? |
- ? |
- 141 |
|
| After |
3 u |
1 u |
3 u - 31 |
109 |
Total number of fruits in the end
= 3 u + 1 u + 3 u - 31
= 7 u - 31
7 u - 31 = 109
7 u = 109 + 31
7 u = 140
1 u = 140 ÷ 7 = 20
Number of kiwis at first
= 3 u - 31 + 141
= 3 x 20 - 31 + 141
= 60 - 31 + 141
= 170
The number of persimmons and kiwis at first was the same.
Number of persimmons used
= 170 - 1 u
= 170 - 20
= 150
Answer(s): 150
