At one sitting, a typical doughnut eater consumes 4 doughnuts containing a total of 680 calories and 40 grams of fat....

Irina on November 30, 2019

@nivensdc,

This is a necessary assumption question, so we are looking for an answer choice that would render the argument invalid if untrue/ when negated. Let's look at the argument.

The argument tells us that a typical doughnut eater consumers a total of 680 calories and 40 grams of fat in one sitting, and a typical bagel eater consumes 500 calories and two grams of fat though the addition of spreads can approximate the calorie & fat content of the four-donut range.

The argument then concludes that as far as total calorie content is concerned, there is little difference between a typical doughnut eater and a typical bagel eater.

Let's look at the answer choices:

(A) The calories in bagels have the same health impact..
Incorrect. The argument is not concerned with the health impact, only the calorie content.

(B) Most bagel eaters are not fully aware of the calorie and fat content of a bagel..
Incorrect. It is irrelevant whether one is aware of the calorie content or not.

(C) Eating bagels instead of eating donuts provides no real health benefit
Incorrect. The argument is not concerned with health benefits, only the total calorie content.

(D) The typical doughnut eater does not add to doughnuts any substances that increase the caloric intake.
Correct. The argument presumes that:
bagel + toppings = 4 donuts

but if a doughnut eater also adds spreads and toppings that increase the caloric intake, then we could conclude that:
bagel + toppings < 4 donuts in terms of calories, which invalidates the argument's conclusion.

Therefore, we must assume that the typical doughnut eater does not any substances that would increase the caloric intake.

(E) Most typical doughnut eaters are not also bagel eater.
Incorrect. The argument compares the calorie intake per one sitting not overall, so even if the groups overlap, there is no impact on the validity of the conclusion.

Let me know if this makes sense and if you have any further questions.