a man sold 20 articles for $ 60 and gained 20 % . how many articles should he sell for $ 60 to incur a loss 20 % ?
"production cost per article : $ 60 * ( 100 % - 20 % ) / 20 = $ 2.40 required production costs for a loss of 20 % : $ 60 * ( 100 % + 20 % ) = $ 72 number of articles to be sold for $ 72 to incur a 20 % loss : $ 72 / $ 2.40 = 30 thus , solution a is correct ."
divide(original_price_before_loss(20, 60), divide(original_price_before_gain(20, 60), 20))