Solve. -Jane Wants to Buy a Photocopier. the Salesperson Has the the Following

Multiple Choice

Solve.
-Jane wants to buy a photocopier. The salesperson has the following information on 3 models. If all 3 are used, a specific job can be done in 50 minutes. If copier A operates for 20 minutes and copier B for 50 minutes, one-half
The job is finished. If copier B operates for 30 minutes and copier C for 80 minutes, three-fifths of the job is done.
Which is the fastest copier, and how long does it take for this copier to finish the whole job?

A) C is fastest; 120 minutes
B) A is fastest; 120 minutes
C) C is fastest; 100 minutes
D) B is fastest; 100 minutes