SSC CHSL Model Paper 19

Let price of sugar = Rs. 100/kg
Expenditure = Rs. 100
New price of sugar = 100 + 21 = Rs. 121
New expenditure = 100 + 12 = Rs. 112
Quantity of sugar bought for Rs. $112=\frac{112}{121}$ kg
Required percent reduction In consumption
$=\frac{1-\frac{112}{121}}{1}\times 100$
$=\frac{121-112}{121}\times 100$
$=\frac{900}{121}=7.43\%$