Petrol price hike - expenditure adjustment
Question
The petrol price shot up by 10% as a result of the hike in crude oil prices. The price of petrol before the hike was 90 per litre. A person travels 2200 km every month and his car gives a mileage of 16 km per litre. By how many km should he reduce his travel if he wants to maintain his expenditure at the previous level?
Options
180 km
200 km
220 km
240 km
Explanation
If the price of a commodity increases by a fraction x/y, consumption must decrease by the fraction x/(x+y) to keep total expenditure constant. Here, the price increases by 10%, which is 1/10.
Therefore, the required reduction in consumption (and thus travel distance) is 1/(10+1) = 1/11. The original distance is 2200 km. Reduction = (1/11) * 2200 = 200 km. The original price (90/litre) and mileage (16 km/l) are decoy data points not needed for the core calculation.
Answer: (b).
Question details
Year
2025
Paper
CSAT
Question
Q7
Section
Numerical Ability
Sub-topic
Percentages & Word Problems
Type
Arithmetic word problem
Difficulty
Medium
Source hint
Percentage application
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