Question Explanations For
Question Types (Understanding)
The Correct Answer is (B) — The question asks you which of these has the lowest smoke point, which the passage tells you is the temperature at which more than 50% of the oil is composed of VFFAs and SCFAs. You may have noticed that that point (50 on the y axis) is marked with a dot for each oil type. The dot with the lowest temperature of the oils you circled is Hemp oil, or (B). If you chose (A), (C), or (D), you may have misread the key or the axis labels.
The Correct Answer is (H) — This question is asking you to read the graph in Figure 2 and find the y-value of the “Second Use” line when it has an x-value of 120°C. This line crosses 120°C a bit below 40% on the y axis, so 38% is the best option. If you chose (F) or (J), you were probably looking at the wrong line. If you chose (G), you may have made too broad of an estimation—while it’s clear that you’re looking at a point between 30% and 40%, it should also be clear that the point is much closer to 40% than to 30%.
The Correct Answer is (D) — The question asks you to refer to Figure 3, and find the temperature where the lines for grapeseed oil and canola oil intersect. The solid and dotted gray lines represent grapeseed and canola oils, respectively, and you can see that they intersect at a temperature between 260°C and 300°C. You don’t need any more precision than that, because (D), or 270°C, is the only answer choice within that range.
The Correct Answer is (G) — The question is asking you to identify how the temperature of the smoke point changes as the oil is reused. You need to know that the smoke point is 50 on the y-axis, marked by a black dot on each curve. Then, you should note the temperature for each curve: when first used, the oil’s smoke point is at 160°C. During its second use, the smoke point drops to about 135°C. At this point, you can eliminate (F) and (H), because there’s an initial decrease. During its third use, the oil’s smoke point is about 115°C, which is lower still, so you can eliminate (J) and choose (G). If you chose (F), you may have forgotten to check the Key, and read the lines backwards.
The Correct Answer is (B) — This question is long and complex, so it’s important to break it up by pausing after each new piece of information, and rephrasing complex phrases into simpler ones. The question asks you to explain how the curves change on the y-axis after the black dot (the smoke point). Looking at Figure 1, you can see that the lines are all straight and positive before they hit the black dot, and afterwards they curve up more steeply. Now you can compare the answer choices, ignoring the parts that repeat. (C) and (D) are incorrect because the trend is increasing before and after the smoke point. (A) is wrong because the curve starts out as linear.