If the price of tea is increased by 20%, by how much percent must the consumption of tea be diminished so as not to increase the expenditure?

Correct option is A

Ans. (c)
Sol.
Let the initial price be ₹100 and initial consumption be 100 units.
So, initial expenditure = 100 × 100 = ₹10,000
Now price increases by 20%,
New price = ₹120
Let new consumption = x units
To keep expenditure same:
120 × x = 10,000
⇒ x = 10,000 / 120 = 83.33 units
Consumption reduced from 100 to 83.33 → decrease = 100 − 83.33 = 16.67 units
% decrease = (16.67 / 100) × 100 = 16⅔%