Anyone know this.......

Answer:
a) The basic rate of pay is 6 sterling pounds per hour.
b) The higher rate of pay is 10 sterling pounds per hour.
Step-by-step explanation:
Both segments of the curve are first order polynomials, which means that each have constant slopes.
a) The basic rate of pay is the value of the slope ([tex]r[/tex]), in sterling pounds per hour, of the line for the first 20 hours worked, that is:
[tex]r = \frac{\Delta y}{\Delta x}[/tex] (1)
Where:
[tex]\Delta x[/tex] - Change in hours worked, in hours.
[tex]\Delta y[/tex] - Change in pay, in sterling pounds.
If we know that [tex]\Delta x = 20\,h[/tex] and [tex]\Delta y = \pounds\, 120[/tex], then the basic rate is:
[tex]r = \frac{\Delta y}{\Delta x}[/tex]
[tex]r = \frac{\pounds\,120}{20\,h}[/tex]
[tex]r = 6\,\frac{\pounds}{h}[/tex]
The basic rate of pay is 6 sterling pounds per hour.
b) By using (1), we calculate the higher rate of pay below. If we know that [tex]\Delta x = 10\,h[/tex] and [tex]\Delta y = \pounds \,100[/tex], then the higher rate is:
[tex]r = \frac{\Delta y}{\Delta x}[/tex]
[tex]r = \frac{\pounds\,100}{10\,h}[/tex]
[tex]r = 10\,\frac{\pounds}{h}[/tex]
The higher rate of pay is 10 sterling pounds per hour.