if 5 % more is gained by selling an article for rs . 420 than by selling it for rs . 380 , the cost of the article is ?
let c . p . be rs . x . then , 5 % of x = 420 - 380 = 40 x / 20 = 40 = > x = 800 answer : e
divide(subtract(420, 380), divide(5, const_100))