3 types of rice, A, B and C, are mixed together in the ratio 1 : 1 : 3 respectively. The price of rice A is Rs. 120 per kg and that of rice B is Rs. 130 per kg. If the price of the mixture is Rs. 150 per kg, then the price of rice C is:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → Rs. 166.66 per kg
Let the price of rice C be Rs. p per kg. The price of the mixture is the weighted average of the prices, with weights 1, 1 and 3:
\( \displaystyle \frac{1(120)+1(130)+3p}{5}=150 \)
\( \displaystyle 250+3p=750 \)
\( \displaystyle 3p=500 \)
\( \displaystyle p=\frac{500}{3}\approx166.66 \)
So rice C costs about Rs. 166.66 per kg.