If the price of a commodity is decreased by 20% and its consumption is increased by 20%, what will be the increase or decrease in expenditure on the commodity?	Choose the most appropriate option:
A) 4% increase B) 4% decrease C) 8% increase D) 8% decrease E) None
Solution: Let the initial expenditure on the commodity be Rs. 100.   Now, the price decreases by 20%,   Current Price = (100 - 20% of 100) = Rs. 80.   Same time due to decrement in price 20% consumption has been increased. So,   Current expenses on commodity = (80 + 20% of 80)= Rs. 96.   Here, the initial expenditure was Rs. 100 which became 96 at the end, it means there is 4% decrement in the expenditure of the commodity.   Mind Calculation Method:   100===20%↓(Decrement in Price)===&gt;80===20%↑(Increment in Consumption)===&gt;96.   Thus, there is a decrement of 4%.   Answer: Option 4% decrease
<result>B</result>
If the price of a commodity is decreased by 20% and its consumption is increased by 20%, what will be the increase or decrease in expenditure on the commodity?