Question

Difficulty: MediumLinear Equations in One and Two Variables

A software consultant charges an enterprise client a fixed setup fee of 200200 dollars plus an hourly rate of rr dollars for 1-on-1 technical training. For team training workshops, the consultant charges a fixed setup fee of 400400 dollars plus an hourly rate that is 50%50\% higher than the 1-on-1 rate. If the client was billed a total of 2,4002,400 dollars for 1212 hours of 1-on-1 training and 88 hours of team training workshops, what is the value of rr?

Answer: 75 dollars per hour

Answer

The individual hourly rate rr is 7575 dollars per hour.
The total cost consists of fixed setup fees (200+400=600200 + 400 = 600) and variable hourly charges (12r+8×1.5r=24r12r + 8 \times 1.5r = 24r). Setting the total cost 600+24r600 + 24r equal to 2,4002,400 and solving for rr yields r=75r = 75.

Step-by-Step Solution

1
Formulate the total cost equation for the 1-on-1 technical training.
Cost1-on-1=200+12r\text{Cost}_{\text{1-on-1}} = 200 + 12r
The client pays a 200200 dollar setup fee plus rr dollars for each of the 1212 hours.
2
Determine the hourly rate and total cost equation for the team training workshops.
Hourly Rateteam=1.5r\text{Hourly Rate}_{\text{team}} = 1.5r, so Costteam=400+8(1.5r)=400+12r\text{Cost}_{\text{team}} = 400 + 8(1.5r) = 400 + 12r
The team hourly rate is 50%50\% greater than rr, which equals r+0.5r=1.5rr + 0.5r = 1.5r. Multiplying by 88 hours yields 12r12r in hourly fees, plus the 400400 dollar setup fee.
3
Combine the total costs to create a single linear equation in terms of rr.
(200+12r)+(400+12r)=2400    600+24r=2400(200 + 12r) + (400 + 12r) = 2400 \implies 600 + 24r = 2400
The total amount billed across both services is given as 2,4002,400 dollars.
4
Isolate the variable rr and calculate its numerical value.
24r=1800    r=7524r = 1800 \implies r = 75
Subtracting 600600 from both sides gives 24r=180024r = 1800, and dividing by 2424 yields r=75r = 75.

Key Concept

Linear Equations in One and Two Variables
Estimated Time:1m 30s
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