When the price of cloth is decreased by 25%, the quantity of cloth sold increased by 20%. What was the effect on gross receipt of the shop?

10% decrease

             Original   :   New

Price:         4        :      3             [25% = \(\frac{1}{4}\)]

Qty :          5        :      6             [20% = \(\frac{1}{5}\)]         

Receipt:    20       :     18

                 10       :      9     ⇒ 1 (decrease)

Decreased percentage = \(\frac{1}{10}\) × 100% = 10%