On decreasing the price of a Air Conditioner by 20%, its sale is increased by 40%. The effect on the revenue is?
Pick
A) 8 % decrease	B) 4 % increase	C) 16% decrease	D) 12 % increase	E) none of these
Net% change in revenue   = ( x + y + xy/100) %   = [-20 + 40 + ( -20 x 40)/100]% or 12%   ANSWER:12 % increase
<result>D</result>
On decreasing the price of a Air Conditioner by 20%, its sale is increased by 40%. The effect on the revenue is?