the cost price of an article is 70 % of the marked price . calculate the gain percent after allowing a discount of 10 % .
"sol . let marked price = rs . 100 . then , c . p . = rs . 70 . s . p = rs . 90 . â ˆ ´ gain % = [ 20 / 70 * 100 ] % = 28.6 % . answer b"
multiply(subtract(divide(subtract(const_100, 10), 70), const_1), const_100)