The price of sugar increases by 15%. By what percentage should the consumption of sugar be decreased so that the expenditure on the purchase of sugar remains the same? [Give your answer correct to 2 decimal places.]

13.04%

15% = \(\frac{3}{20}\)

Ratio ,             Initial    :    Final

Price                  20      :     23

Consumption         23   :     20

{  consumption ∝ \(\frac{1}{Price}\) }

Required percentage = \(\frac{23-20}{23}\) × 100 = 13.0434%

= 13.04%  (approx)