Question: If 12 men and 16 boys can do a piece of work in 5 days & 13 men and 24 boys can do it in 4 days, how long will 7 men & 10 boys takes to do it? . . .

Question: A can do a piece of work in 10 days, B in 12 days & C in 15 days. All being together but A leaves the work after 2 days and B leaves 3 days before the work is finished. How long did the work last? . . .

Question: A can do a piece of work in 10 days, B in 18 days, & A, B & C together in 4 days. In what time would C alone do it? . . .