Multiple choice

A barrel contains a mixture of 80 litres petrol, 50 litres kerosene and 20 litres diesel. ______ litres of the given mixture is drawn and _______ litres of kerosene and ______ litres of diesel are added. The final mixture has 64 litres petrol, 65 litres kerosene and 66 litres diesel. Which of the following options satisfies the three blanks in the question? A. 30, 25, 50 B. 20, 50, 40 C. 22, 44, 50 D. 30, 40, 50

  1. B

  2. C

  3. D

  4. A

  5. Only B and C
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Initial: P=80, K=50, D=20. Total=150. Let x be amount drawn. Remaining: P=80-80x/150, K=50-50x/150, D=20-20x/150. Add k_add and d_add. Final: 80 - 8x/15 = 64 => 8x/15 = 16 => x = 30. K: 50 - 50(30)/150 + k_add = 65 => 50 - 10 + k_add = 65 => k_add = 25. D: 20 - 20(30)/150 + d_add = 66 => 20 - 4 + d_add = 66 => d_add = 50. Matches option A.

AI explanation

By testing option A, we assume 30 litres of the 150-litre mixture is drawn. Petrol makes up 80/150 of the mixture, so the remaining petrol is 80 minus 30 times 80/150, which equals 64 litres. This matches the final petrol quantity, and applying the same replacement for kerosene gives 50 minus 10, leaving 40 litres, plus 25 litres added to equal 65 litres. For diesel, 20 minus 4 leaves 16 litres, plus 50 litres added gives 66 litres. Therefore, option A satisfies all conditions.

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