There were some apples, starfruits and pomegranates. The number of apples was three times the number of starfruits. The total number of apples and starfruits was half of the number of pomegranates. There were 180 fruits altogether. All the pomegranates were sold at 4 for $13. How much money was collected from the sale of the pomegranates?
Number of starfruits = 1 u
Number of apples = 3 u

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

Number of pomegranates
= 2 x 4 u
= 8 u

Total number of fruits
= 1 u + 3 u + 8 u
= 12 u

12 u = 180

1 u = 180 ÷ 12 = 15

Number of pomegranates sold
= 8 u
= 8 x 15
= 120

Number of sets of 4 pomegranates
= 120 ÷ 4
= 30

Amount collected from the sale of pomegranates
= 30 x 13
= $390

Answer(s): $390