a can do a piece of work in 5 days and b can do it in 7 days how long will they both work together to complete the work ?
"explanation : a ’ s one day work = 1 / 5 b ’ s one day work = 1 / 7 ( a + b ) ’ s one day work = 1 / 5 + 1 / 7 = 12 / 35 = > time = 35 / 12 = 2 9 / 12 days answer : option d"
divide(const_1, add(divide(const_1, 5), divide(const_1, 7)))