Explanation for Question 13 From the Math (Calc) Section on the 2018 March Sat
Question 13 says the graph above shows the price that a chemical company charges 2 for an order fragrance oil, depending on the weight of the order, 3 based on the graph, which of the following statements must be true. 4 So all of these statements talk about the change in price per pound 5 for orders. So the first thing we know is we know that there is 6 a change because we can clearly see the slope of this line is steeper 7 than the slope of this line. And we also know that that change occurs 8 at a hundred pounds. So from that information alone, 9 we can eliminate C and D D is wrong because it says there is 10 no change. And we know that there is and see us wrong because it 11 says that the change happens at a thousand pounds. 12 When we know it happens at a hundred pounds, 13 finally, we know that the correct answer is B that the company charges less 14 per pound for orders greater than a hundred pounds than for orders, 15 less than a hundred pounds. Because we can see that the slope of the 16 line after a hundred pounds is less steep, 17 which means that the price is increasing at a slower rate. 18 So that means that B is the correct answer.