the cost price of an article is 25 % of the marked price . calculate the gain percent after allowing a discount of 50 % .
"sol . let marked price = rs . 100 . then , c . p . = rs . 25 . s . p = rs . 50 . â ˆ ´ gain % = [ 25 / 25 * 100 ] % = 100.0 % . answer c"
multiply(subtract(divide(subtract(const_100, 50), 25), const_1), const_100)