SAT Math Multiple Choice Question 296: Answer and Explanation
11. Some herbicides are more effective at killing weeds than others, relative to the amount of the herbicide needed to produce results. Which graph could represent the effectiveness of a more-effective herbicide, m, and a less-effective herbicide, l?
Correct Answer: C
Category: Heart of Algebra / Linear Equations
Strategic Advice: Sometimes, the best way to answer a conceptual question, particularly one that involves graphs without number labels, is to add your own numbers to the graph. Then you can try to make sense of the axis labels and the numbers you added.
Getting to the Answer: Add reasonable numbers to each graph that make sense for that graph. (C) is correct because logically, a more-effective herbicide requires fewer ounces to eliminate all of the weeds. In the sample graph below, the more effective herbicide (which is m) only takes 3 ounces to achieve 0% weeds remaining, while the less effective one (which is l) takes 5 ounces to produce the same results.