Trent can deliver his newspapers in 4040 minutes. It takes Lois 1010 minutes to do the same route. How long would it take them to deliver the newspapers if they work together?

808 minutes

Explanation:

Let the time taken by Trent be A and the time taken by Lois be B.

The total time (T) it will take both of them if they work together is given by the equation below;

Total time (T) =   (AB)/(A+ B)

                      = (4040 x 1010)/(4040 + 1010)

                      = 4,080,400/5050

Total time      = 808 minutes.

answer; face validity;