A trade analyst announced 20% reduction in the unit price of car. As a result, the sales volume went up by 5%. What was the net effect on the sales revenue?
Choose the correct answer.
A) no change B) decreases by 19.2% C) increases by 19% D) increases by 19.0% E) None of these
Explanation :   Reduction of price = (100 -20)= 
<gadget id="calculator">(100 -20)</gadget>
<output>80</output>
80%= 0.8   Increase of sale = (100+5)= 
<gadget id="calculator">(100+5)</gadget>
<output>105</output>
105%= 1.05   Total effect = 0.8 X 1.01 = 80.8%, Decreases by 19.2%   Answer : decreases by 19.2%
<result>B</result>
A trade analyst announced 20% reduction in the unit price of car. As a result, the sales volume went up by 5%. What was the net effect on the sales revenue?