There were some pears, chikoos and oranges. The number of pears was two times the number of chikoos. The total number of pears and chikoos was half of the number of oranges. There were 180 fruits altogether. All the oranges were sold at 4 for $13. How much money was collected from the sale of the oranges?
Number of chikoos = 1 u
Number of pears = 2 u

Total number of chikoos and pears
= 1 u + 2 u
= 3 u

Number of oranges
= 2 x 3 u
= 6 u

Total number of fruits
= 1 u + 2 u + 6 u
= 9 u

9 u = 180

1 u = 180 ÷ 9 = 20

Number of oranges sold
= 6 u
= 6 x 20
= 120

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

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

Answer(s): $390