Time and work
Commercial arithmetic · Mathematics
Study notes
Q: A finishes in 6 days, B in 12 days. Together? A pipe fills in 4 hrs, another empties in 6 hrs. Net? Part A: Combined rate = 1/6 + 1/12 = 3/12 = 1/4 → 4 days together. Part B: Net rate = 1/4 − 1/6 = 1/12 → fills in 12 hours.