Albert and Bryan can do a certain task if both work together 3 days and Albert then works alone 1 day.
Albert and Bryan can do a certain task if both work together 3 days and Albert then works alone 1 day. Bryan and Carl can do it if Bryan works 3 days and Carl works 10 days. It would take Carl 9 days longer than it would take Albert to do it alone. How long would Albert take if working alone?