Mary takes 8 days to do a full check of the library's online catalog. Her assistant takes
12 days. If they work together, determine the
fraction of the catalog that is checked after
4 days.

*let m∠cob = 50°30’, m∠aob = 70° and m∠aoc = 20°30’. could point c be in the interior of ∠aob? why? a. point c could be the interior of aob but it is not the only case b. point c is the interior of aob c. point c is not the interior of aob d. the given is not possible for the plane geometry answer