10•8=80
so something times 80 will equal 400
80•5=400
Let N be the number of items sold and p the price.
Since the variation is inverse, then the relation between N and p is:

For N=20000 and p = $9.5, we get the formula:

If p = 8.75, then the number of items sold can be computed using the formula:
The answer is either A or D, B and C are off the table because the two shapes need to be graphed for those to be relevant. The answer you get should be A I believe.