Answer:
Electrician = $20 per hour
Plumber = $52 per hour
Step-by-step explanation:
To find the hourly wages for both the electrician and the plumber, we can set up a system of equations based on the given information.
Let x be the hourly wage for the electrician (in dollars per hour).
Let y be the hourly wage for the plumber (in dollars per hour).
If the average of an electrician's hourly wage and a plumber's hourly wage is $36, then:

Given a contractor hires an electrician for 8 hours of work and the plumber for 5 hours of work, and pays a total of $420 in wages, then:

Therefore, the system of equations is:

Rearrange the first equation to isolate x:

Substitute the expression for x into the second equation and solve for y:

Substitute the found value of y into the expression for x and solve for x:

Therefore, the hourly wage for the electrician is $20, and the hourly wage for the plumber is $52.