A wholesaler bought walnuts and peanuts, the price of walnut per kg being thrice that of peanut per kg . He then sold of peanuts at a profit of and of walnuts at a profit of to a shopkeeper. However, the shopkeeper lost of walnuts and of peanuts in transit. He then mixed the remaining nuts and sold the mixture at Rs. per kg, thus making an overall profit of . At what price, in Rs. per kg, did the wholesaler buy the walnuts?
A wholesaler bought walnuts and peanuts, the price of walnut per kg being thrice that of peanut per kg . He then sold of peanuts at a profit of and of walnuts at a profit of to a shopkeeper. However, the shopkeeper lost of walnuts and of peanuts in transit. He then mixed the remaining nuts and sold the mixture at Rs. per kg, thus making an overall profit of . At what price, in Rs. per kg, did the wholesaler buy the walnuts?
Solution
We have a chain of transactions: wholesaler → shopkeeper → final customer. Let us track the costs and profits step by step.
Let the cost price of peanuts for the wholesaler = per kg
Since walnut price is thrice that of peanut price:
Cost price of walnuts for the wholesaler = per kg
We choose the simpler variable (peanut price) as our base, making calculations easier.
The wholesaler sold:
8 kg peanuts at 10% profit
16 kg walnuts at 20% profit
Understanding profit calculation:
10% profit means selling price = cost price × 1.1
20% profit means selling price = cost price × 1.2
Shopkeeper's total cost price = Amount paid to wholesaler
For peanuts: 8 kg × × 1.1 =
For walnuts: 16 kg × × 1.2 =
Total cost price for shopkeeper =
The shopkeeper lost some nuts in transit:
Lost 5 kg walnuts → Remaining walnuts = 16 - 5 = 11 kg
Lost 3 kg peanuts → Remaining peanuts = 8 - 3 = 5 kg
Total mixture sold = 11 + 5 = 16 kg
Shopkeeper sold 16 kg at Rs. 166 per kg
Total selling price = 16 × 166 = Rs. 2656
Key insight: We know the shopkeeper made 25% overall profit, so:
Selling Price = Cost Price × 1.25
Therefore: Cost Price = Selling Price ÷ 1.25
Cost Price = 2656 ÷ 1.25 = 2656 × = Rs. 2124.8
Why ? Because 1.25 = , so 1 ÷ 1.25 =
We now have two expressions for the shopkeeper's cost price:
From wholesaler calculation:
From profit calculation:
Setting them equal:
Price at which wholesaler bought walnuts = Rs. 96 per kg