UPSC Prelims 2025·CSAT·Quantitative Aptitude·Arithmetic

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 π 90 per litre. A person travels 2200km every month and his car gives a mileage of 16km per litre. By how many km should he reduce his travel if he wants to maintain his expenditure at the previous level?

Dalvoy logo
Reviewed by Dalvoy
UPSC Civil Services preparation
Last updated 23 May 2026, 3:31 pm IST
  1. A180km
  2. B200kmCorrect
  3. C220km
  4. D240km

Explanation

1. Calculate original monthly petrol consumption: 2200 km / 16 km/litre = 137.5 litres. 2. Calculate original monthly expenditure: 137.5 litres * Rs 90/litre = Rs 12375. 3. Calculate the new petrol price: Rs 90 + 10% of Rs 90 = Rs 90 + Rs 9 = Rs 99 per litre. 4. To maintain the expenditure at the previous level (Rs 12375), the person can now buy: Rs 12375 / Rs 99/litre = 125 litres of petrol. 5. Calculate the new travel distance possible with 125 litres: 125 litres * 16 km/litre = 2000 km. 6. Calculate the reduction in travel: Original travel (2200 km) - New travel (2000 km) = 200 km. Therefore, he should reduce his travel by 200 km. Option B is correct. Option C (220km) would be incorrect if one mistakenly reduced the travel by 10% of the original distance (2200 * 0.10 = 220), which is a common error in such problems. The reduction in quantity (and thus distance) is not directly proportional to the percentage increase in price when expenditure is kept constant.
Quantitative Aptitude: 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 π 9
ShareWhatsAppXTelegram

Related questions

More UPSC Prelims practice from the same subject and topic.