If the price of a commodity rises by $40\%$, by what percent should consumption fall so that total expenditure remains unchanged?
Practice this question from Chapter Mock 3: Percentage, with options and an explanation.
Question
If the price of a commodity rises by $40\%$, by what percent should consumption fall so that total expenditure remains unchanged?
Option A
$25\%$
Option B
$26\frac23\%$
Option C — Correct answer
$28\frac47\%$
Correct choice.
Option D
$30\%$
Explanation
Required reduction $=\frac{40}{100+40}\times100=\frac{40}{140}\times100=28\frac47\%$.