We have been given that Jeanne claims that she will need to sell 300 cakes in order for the cost of producing cakes to equal the revenue brought in by selling the cakes.
Cost and revenue are equal for break even. This can be found graphically using one of the three methods:
1) By graphing both cost and revenue functions and looking for the intersection point. x must be 300 at the intersection point.
2) Secondly, we can graph the function y = C(x) – R(x) and the line y = 0 and look for the intersection. x must be 300 at the intersection point.
3) Finally, we can graph y = C(x) – R(x) and look for its x intercepts. One of the x intercepts must be 300.
Now let us choose the correct option from the given choices.
Option (A) is wrong because at intersection point, the x coordinate should be 300 rather than y coordinate.
The other three options, (B), (C) and (D) are absolutely right.