There were some starfruits, lemons and mangoes. The number of starfruits was two times the number of lemons. The total number of starfruits and lemons was one-quarter of the number of mangoes. There were 180 fruits altogether. All the mangoes were sold at 8 for $10. How much money was collected from the sale of the mangoes?
Number of lemons = 1 u
Number of starfruits = 2 u

Total number of lemons and starfruits
= 1 u + 2 u
= 3 u

Number of mangoes
= 4 x 3 u
= 12 u

Total number of fruits
= 1 u + 2 u + 12 u
= 15 u

15 u = 180

1 u = 180 ÷ 15 = 12

Number of mangoes sold
= 12 u
= 12 x 12
= 144

Number of sets of 8 mangoes
= 144 ÷ 8
= 18

Amount collected from the sale of mangoes
= 18 x 10
= $180

Answer(s): $180