x is 3 times as fast as y and working together , they can complete a work in 20 days . in how many days can y alone complete the work ?
x = 3 y x + y = 3 y + y = 4 y these 4 y people together can do the work in 20 days , which means y can alone do the work in 4 * 20 = 80 days . answer : b
multiply(add(3, const_1), 20)