First of all, a positive average rate of change means that the function is increasing, so the answer can only be A->B or B->C.
The average rate of change is defined as

i.e. as the ratio between the vertical and horizontal gain.
In order to go from point A to point B, you gain 1 unit horizontally and 5 units vertically. So, the average rate of change is 5/1=5.
In order to go from point B to point C, you gain 1 unit horizontally and 3 units vertically. So, the average rate of change is 3/1=3.
Answer:
profit is 25%
Step-by-step explanation:
profit%=sp-cp/cp×100%
=350-280/280×100%
=0.25×100
=25%
Nine less than a number
is
n - 9
The first one is 10.5
The second is y10
And the third is 7