There were some mangosteens, apples and starfruits. The number of mangosteens was three times the number of apples. The total number of mangosteens and apples was one-third of the number of starfruits. There were 160 fruits altogether. All the starfruits were sold at 8 for $8. How much money was collected from the sale of the starfruits?
Number of apples = 1 u
Number of mangosteens = 3 u

Total number of apples and mangosteens
= 1 u + 3 u
= 4 u

Number of starfruits
= 3 x 4 u
= 12 u

Total number of fruits
= 1 u + 3 u + 12 u
= 16 u

16 u = 160

1 u = 160 ÷ 16 = 10

Number of starfruits sold
= 12 u
= 12 x 10
= 120

Number of sets of 8 starfruits
= 120 ÷ 8
= 15

Amount collected from the sale of starfruits
= 15 x 8
= $120

Answer(s): $120