In what ratio should coffee powder costing Rs. 500 per kg be mixed with coffee powder costing Rs. 750 per kg so that the cost of the mixture is Rs. 600 per kg?

Correct option is C

1. Cost of coffee powder 1 (C1) = Rs. 500 per kg
2. Cost of coffee powder 2 (C2) = Rs. 750 per kg
3. Cost of the mixture (Cm) = Rs. 600 per kg
Using the rule of alligation, we have:
​$$\frac{(C2 - Cm)} {(Cm - C1)} = \frac{(750 - 600)}{ (600 - 500)}\\\frac{(C2 - Cm)} {(Cm - C1)} = \frac{150}{100}= \frac32$$​​
Therefore, the ratio in which the two coffee powders should be mixed is 3:2.