Given: Increase in the cost of cooking oil by 45% Decrease in the consumption of oil by 20% Formula Used: If the successive increase in percentages be a% and b%. In that case, the total increase will be (a+b+
ab
100
)% Calculation: According to the question, The net effect of the successive percentage change =45+(−20)+
45×(−20)
100
⇒ 45 – 20 – 9 ⇒ 16 ∴ The expenditure for oil of that consumer will be increased by 16%.