A store owner had the same number of mangoes, mangosteens and starfruits at first. After 108 starfruits, some mangoes and mangosteens were removed, there were 99 fruits left. There were thrice as many mangoes as mangosteens left. The number of starfruits left was 20 less than the number of mangoes. How many mangosteens were removed?
| |
Mangoes |
Mangosteens |
Starfruits |
Total |
| Before |
1 |
1 |
1 |
|
| Change |
- ? |
- ? |
- 108 |
|
| After |
3 u |
1 u |
3 u - 20 |
99 |
Total number of fruits in the end
= 3 u + 1 u + 3 u - 20
= 7 u - 20
7 u - 20 = 99
7 u = 99 + 20
7 u = 119
1 u = 119 ÷ 7 = 17
Number of starfruits at first
= 3 u - 20 + 108
= 3 x 17 - 20 + 108
= 51 - 20 + 108
= 139
The number of mangosteens and starfruits at first was the same.
Number of mangosteens removed
= 139 - 1 u
= 139 - 17
= 122
Answer(s): 122
