At a fruit stall, 392 mangosteens were sold in the morning and ⁴₇ of the remaining mangosteens were sold in the afternoon. As a result, the number of mangosteens left became ¹₅ of the total number of mangosteens at first. Given that the mangosteens were sold at $2.50 in packs of seven mangosteens, how much did the fruit stall receive from the sale of the mangosteens in the afternoon?
Fraction of the remaining mangosteens left
= 1 - ⁴₇
= ³₇

Make numerators the same.
³₇ of remaining mangosteens = ¹₅ of total mangosteens
³₇ of remaining mangosteens = ³₁₅ of total mangosteens

15 u - 7 u = 392
8 u = 392
1 u = 392 ÷ 8 = 49

Number of mangosteens sold in the afternoon
= 4 u
= 4 x 49
= 196

Number of packs of seven mangosteens sold in the afternoon
= 196 ÷ 7
= 28

Amount received for mangosteens sold in the afternoon
= 28 x 2.50
= $70

Answer(s): $70