Julio is paid 1.3 times his normal hourly rate for each hour he works over 30 hours in a week. Last week he worked 45 hours and earned $554.40.

Enter and solve an equation to find Julio's normal hourly rate, r. Complete the explanation how you know that your answer is reasonable.

(Mostly need the equation)

Respuesta :

Answer:

  $11.20 per hour

Step-by-step explanation:

You want to know Julio's base pay when he worked 45 hours and earned $554.40, including a 30% premium for hours over 30.

Setup

For pay p per hour for h hours, Julio's pay is ...

  pay = p·h +0.3p·(h -30)

Using the given values of pay and hours, we have ...

  554.40 = p(45) +0.3p(45 -30) . . . . . . . equation with given values

  554.40 = 45p +4.5p

  554.40 = 49.5p . . . . . . simplified equation

Solution

Dividing by the coefficient of p gives ...

  p = $554.40/(49.5 h) = $11.20/h

Julio's normal hourly rate is $11.20 per hour.

Reasonableness check

At this rate, 45 hours of straight time would give pay of about ...

  $11.20 h × 45/h = $504

His overtime pay is for 0.3(45 -30) = 4.5 hours, which is 10% more than his 45 straight time hours. That adds 10% to the pay, making the total ...

  $504 +50.4 = $554.40 . . . . . matching the given amount

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Additional comment

The equation including the factor (h-30) is only valid for values of h that are at least 30. If Julio works 30 or fewer hours, his pay is ...

  pay = ph . . . . . where p = 11.20

Effectively, the equation for pay is a piecewise-defined function. In this problem, we're only concerned with the piece that applies for h>30.