a and b complete a work in 6 days . a can alone can do it in 10 days . if both can together can do the work in how many days ?
1 / 6 + 1 / 10 = 8 / 30 = 4 / 15 15 / 4 = 3.75 days answer b
divide(multiply(6, 10), add(6, 10))