The cost of Type 1 rice is Rs. 15 per kg and Type 2 rice is Rs. 20 per kg. If…

2023

The cost of Type 1 rice is Rs. 15 per kg and Type 2 rice is Rs. 20 per kg. If both Type 1 and Type 2 are mixed in the ratio of 2 : 3, then the price per kg of the mixed variety of rice is:

  1. A.

    Rs. 18

  2. B.

    Rs. 18.50

  3. C.

    Rs. 17

  4. D.

    Rs. 16.18

Attempted by 15 students.

Show answer & explanation

Correct answer: A

Solution: Find the price per kg of the mixed rice using a weighted average.

  1. Mixing ratio (Type 1 : Type 2) = 2 : 3.

  2. Price of Type 1 = Rs. 15 per kg; Price of Type 2 = Rs. 20 per kg.

  3. Weighted average = (2 × 15 + 3 × 20) / (2 + 3) = (30 + 60) / 5 = 90 / 5 = 18.

  4. Therefore the price per kg of the mixed variety is Rs. 18.

  • Alternative (allegation) check: difference between 20 and 18 is 2, difference between 18 and 15 is 3, which gives the ratio 2:3 — consistent with the mixing ratio.

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