How much rice of ₹4 per kg should be mixed to 15 kg of rice of ₹10 per kg, so as to make a mixture worth ₹6.50 per kg?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 21 kg.
Let the amount of rice at ₹4 per kg = x kg
Total cost of the first type of rice = 4x
Total cost of the second type of rice = 15 × 10 = 150
So, 4x + 150 = 6.50(x + 15)
⇒ 4x + 150 = 6.5x + 97.5
⇒ 2.5x = 52.5
⇒ x = 52.5/2.5 = 21
Therefore, 21 kg of rice at ₹4 per kg should be mixed.