Word problem about speed.

Question

Two computers are available to run a complicated program. The first, Arnetik, can complete the program in 6 hours. The second, Betakin, can do it in only 4 hours. If the two computers are networked and the program is run on that network, how long should it take?Word

Answer 1

Arnetik has work rate 1/6 of the processing per hour while Betakin has work rate 1/4 of the process per hour

the combined work-rate is 1/6 + 1/4 = 2/12 + 3/12 = 5/12

Therefore, they will complete the task is 12/5 hours or 2 hours and 24 minutes