The price of rice is decreased by 10%. Find by how much percent a man should increases his consumption so that the expenditure remains same?

11\(\frac{1}{9}\)%

Price × Consumption = Expenditure

*(If expenditure remains same the price is inversely proportional to consumption)

Therefore,

10% = \(\frac{1}{10}\)

Price ratio:         10    :    9

Consumption:     9     :   10   ⇒ 1 (increased by)

Hence,

Increased percentage = \(\frac{1}{9}\) × 100% = 11\(\frac{1}{9}\)%