Ted can change an advertisement on a billboard in 5hr. Marie can do the same job in 2hr. How long would it take them if they worked together? Write your answer as a fraction or mixed number, if necessary.

Working together, they will finish the job in 1 hour, 25 minutes, and 42.6 seconds.

Step-by-step explanation:

Given that Ted can change an advertisement on a billboard in 5 hours, while Marie can do the same job in 2 hours, to determine how long it would take them if they worked together the following calculation must be performed:

Ted 1/5 in 1 hour

Marie 1/2 in 1 hour

1/5 + 1/2 = X

5X + 2X = 10

7X = 10

X = 10/7

X = 1 3/7

60/7 x 3 = 25.71

60 x 0.71 = 42.6

So, working together, they will finish the job in 1 hour, 25 minutes, and 42.6 seconds.

answer: .75 km

step-by-step explanation: