a dishonest dealer professes to sell goods at the cost price but uses a weight of 780 grams per kg , what is his percent ?
"780 - - - 220 100 - - - ? = > 28.2 % answer : e"
subtract(multiply(divide(const_100, 780), multiply(const_100, multiply(add(const_3, const_2), const_2))), const_100)