a man sold 20 articles for $ 40 and gained 20 % . how many articles should he sell for $ 90 to incur a loss 20 % ?
"production cost per article : $ 40 * ( 100 % - 20 % ) / 20 = $ 1.6 required production costs for a loss of 20 % : $ 90 * ( 100 % + 20 % ) = $ 108 number of articles to be sold for $ 108 to incur a 20 % loss : $ 108 / $ 1.6 = 67.5 thus , solution e is correct ."
divide(original_price_before_loss(20, 90), divide(original_price_before_gain(20, 40), 20))