The correct option is C Company B
Detailed step-by-step solution:
Finding the equation of company A:
Let the equation be y=mx+b, where x represents the working time (in hr) and y represents the earning amount ($).
y-intercept is the value of y when x=0.
Basic pay =$1100 (basic pay is the pay when no hours of work is done)
I.e., at x=0,y=$1100.
⇒ y-intercept, b=1100
Unit rate = Slope (m)=$60 per hour
The equation will be y=60x+1100.
Total earning from Company A in a week:
Total earnings from Company A in a week will be the value of y when x=40 (total working hours in a week).
⇒y=60(40)+1100
⇒y=2400+1100
⇒y=3500
Total earning from Company A in a week =$3500
Finding the equation of Company B:
Since the line passes through the origin, the line is in the form y=mx.
From the graph, consider two points (0,0) and (20,1800).
Slope=RiseRun
=Change in yChange in y
=1800−020−0
=180020
=90
The equation will be y=90x.
Total earning from Company B in a week:
Total earning from Company B in a week will be the value of y when x=40 (total working hours in a week).
⇒y=90(40)
⇒y=3600
Total earning from company B in a week =$3600.
Finding the equation of Company C:
Let the equation be y=mx+b, where x represents the working time (in hr) and y represents the earning amount ($).
Basic pay from company C = $400 + (Basic pay from company A)
=$400+$1100=$1500
I.e., at x=0,y=$1500.
y-intercept is the value of y when x=0.
⇒ y-intercept, b=1500
Hourly rate of pay from Company C=12 (Hourly rate of pay from Company B)
Slope of the equation of Company C (m)=12 (Slope of the equation of Company B)
=12×90=45
The equation will be y=45x+1500.
Total earnings from Company C in a week:
Total earning from Company C in a week will be the value of y when x=40 (total working hours in a week)
⇒y=45(40)+1500
⇒y=1800+1500
⇒y=3300
Total earnings from Company C in a week =$3300
Out of the three companies, earnings from Company B is highest, i.e., $3600 in a week.
Hence, Company B’s offer is the best.
⇒ Option B is correct.