Question

Shawn and Ellie are construction workers. Shawn can complete a concrete job in 4 hours, while Ellie can complete it in 6 hours. The foreman says that it will take them 5 hours to complete it if they work together. Explain each step in solving this equation, and determine if the foreman is correct or not.

Answer 1

If I'm right, the foreman said that it would take the average amount of time to complete a job-since 5 hours is the average amount of time that it takes Shawn and Ellie to complete a job.
The work:
6(Ellie)+4(Shawn)=10/2(number of variables)=5 hours. 
Hope I helped!