The price of cooking gas has increased by 25%. By what percent should a family reduce the use of cooking gas so as not to increase the expenditure in this account ?
Answer & explanation
Correct answer: option 2
Price × Consumption = Expenditure,
{If expenditure is same then Price is inversely proportional to consumption}
25% = \(\frac{25}{100}\) = \(\frac{1}{4}\)
Old : New
Price: 4 : 5
Consumption: 5 : 4 = 1 (Reduced by)
Percentage of reduction = \(\frac{1}{5}\) × 100% = 20%