Multiple choice

The gas station owner, who lacks honesty, claims to sell pure petrol at its original cost, but in reality, he/she mixes it with some impure liquid to make a profit of 28%. If the impure liquid is readily accessible, what percentage of this impure liquid is present in the mixture?

  1. 80.752%

  2. 87.525%

  3. 21.875%

  4. 20.875%
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

To get a 28% profit by selling at cost, the ratio of impure liquid to pure petrol must be 28/100. The mixture consists of 100 parts petrol and 28 parts impurity. The percentage of impurity is 28 / (100 + 28) = 28 / 128 = 0.21875, or 21.875%.

AI explanation

Let the cost of one liter of pure petrol be Rs. 100 and the volume of the mixture be one liter. By selling this mixture at the original price, the shopkeeper collects Rs. 100 but only values the actual petrol at Rs. 100, which indicates the true cost to him was based on the pure petrol volume. Since a 28% profit means the true cost of the pure petrol used was 100 divided by 1.28, equating to Rs. 78.125. The impure liquid makes up the remaining 21.875% of the mixture.

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