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

shawn does 1 job in 6 hours

turn that into a fraction 1/6

Ellie 1 in 4 so fraction is 1/4

1/6 + 1/4 = 5/12

12/5 = 2.4

it will take them 2.4 hours