a can do a job in 18 days and b can do it in 30 days . in how many days will they finish it together ?
explanation : 1 / 18 + 1 / 30 = 8 / 90 = 4 / 45 so , both together will finish the work in 4 / 45 days . answer : b
add(divide(const_1, 18), divide(const_1, 30))