Answer:
67%
Step-by-step explanation:
Cost plus markup = selling price.
Here, the cost was $30 and the selling price was $50. Subtracting $30 from $50, we get $20, which was the dollar amount of the markup.
We now compare this $20 to the original cost ($30):
$20
------- * 100^ = 67%
$30
The markup, as a percentage, was 67%.
Graph K. This is because the cost of a gallon of milk is not increasing constantly, as in a linear rate, but it has only increased a few times in a year. Therefore, graph K shows that a gallon of milk is a steady, unchanged price, then the cost rises and stays the same, then rises again and stays the same. So, it is not a linear graph because the cost of the milk is not going up at a constant rate.