One-third of goods are sold at a 15% profit. 25% of the goods are sold at a 20% profit and the rest at a 20% loss. If the total profit of ₹138.50 is earned on the whole transaction, then the value(in ₹) of the goods is:

₹8,310

Let the quantity = 120

one third sold at 15% profit means, 

= \(\frac{120}{3}\) = 40

SP of 40 = \(\frac{40 x 115}{100}\)  = 46

25% = \(\frac{120}{4}\) = 30

SP of 30 = \(\frac{30 x 120}{100}\) = 36

Remaining 50 is sold at 20% loss

SP of 50 = \(\frac{50 x 4}{5}\) = 40

Profit = Total selling price - Total cost price

       ( 46 + 36 + 40) - (120) = 2

2x = 138.50 

120x = ₹8,310