Question

The Office Jet printer can copy Janet's dissertation in 10 min. The Laser Jet printer can copy the same documents in 8 min. If the two machines work together, how long would they take to copy the dissertation?

10*8=80
80/18= 4.4
so it would take 4 min. is this correct?

Answer 1

4 min won't do it. It will take 4.4 as your original calculation shows.

Answer 2

The OfficeJet printer can copy Janet's dissertation in 16 min. The LaserJet printer can copy the same document in 8 min. If the two machines work​ together, how long would they take to copy the​ dissertation?

Answer: 5 1/3