Question

A mixture of 12 kg of wheat flour costing Rs. 16 per kg and 4 kg of corn flour costing Rs. 2 per kg is sold at Rs. 16 per kg. What is the profit made in selling 40 kg of the mixture?

• A. Rs. 140
• B. Rs. 280
• C. Rs. 300
• D. Rs. 420

Hint:

Find the weighted average cost price per kg of the mixture, subtract it from the selling price to get profit per kg, then multiply by 40.

Answer 1

The Correct Option is A

Step 1: Find the cost price of the mixture per kg.
The batch consists of 12 kg of wheat flour at Rs. 16/kg and 4 kg of corn flour at Rs. 2/kg, a total of 16 kg.
Total cost = 12(16) + 4(2) = 192 + 8 = Rs. 200
Cost price per kg of the mixture = \( \dfrac{200}{16} = \) Rs. 12.5

Step 2: Find the profit per kg and scale up to 40 kg.
The mixture is sold at Rs. 16 per kg, so profit per kg = 16 - 12.5 = Rs. 3.5
Since the wheat and corn are always mixed in the same 12:4 (that is 3:1) ratio, this profit per kg applies to any quantity of the mixture sold, including 40 kg.
Profit on 40 kg = 40 x 3.5 = Rs. 140

Final Answer:
The profit made on selling 40 kg of the mixture is Rs. 140. Answers like Rs. 280 or Rs. 300 come from errors such as using the wrong cost price per kg or forgetting to average the two flour costs by weight. \[ \boxed{\text{Profit} = \text{Rs. } 140} \]