Question

Observe the graph given below.
Find the total money earned (in $) for working 5 hours.

• A. 5
• B. 7.5
• C. 10
• D. 10.5

Answer 1

The correct option is D 10.5

From the graph, you can observe:
Inital value = y-intercept = $\$5$
Total time worked is 5 hours.

You know,
Slope = rate of change =$\frac{Changeiny}{Changeinx}$

Consider the points $(1,6.1)$ and $(2,7.2)$
Now, amount earned per hour will be equal to the slope of the graph.
∴ Slope of the graph =$\frac{7.2-6.1}{2-1}=1.1$

You know, equation of a straight line is given by $y=mx+c$ where c represenst the y-intercept.

So, putting the values you get the equation as:
$y=1.1x+5$

∴ When $x=5$, pocket money earned will be = $1.1\times 5$ = $\$5.5$

So, total pocket money earned in 5 hours = $\$5+\$5.5$
= $\$10.5$