Question
A commodity's price rises by 32%, and as a result, a
person reduces their consumption by 15%. What is the overall change (percentage increase or decrease) in their total expenditure?Solution
Let original amount of the commodity bought by the person be ‘x’ unit and price of that commodity be Rs. ‘y’ per unit Initial expenditure = Rs. xy Now, increased price = Rs. 1.32y Decreased consumption = 0.85x New expenditure = 1.32y × 0.85x = Rs. 1.122xy Required percentage = {(1.122xy – xy)/xy} × 100 = 12.2%
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