Okay so we have another Strengthen with Sufficient Premise question. Remember that a sufficient premise is sufficient for a conclusion, if and only if the existence of the premise guarantees or brings about the existence of the conclusion.Therefore, we need to find the premise that 100% guarantees the conclusion. The way you want to attack these answer choices is two-pronged. Ask yourself, does it strengthen? If it doesn't, then cross it out and continue to the next answer choice. If it does strengthen, however, then ask yourself whether or not the premise 100% guarantees the conclusion.
The conclusion of the argument is: less money is being spent now on effective treatments of disease X than was spent 10 years ago. Why? Because in the past 10 years, a decreasing percentage of money spent on treating disease X went to pay for standard methods of treatment, and an increasing percentage is being spent on nonstandard treatments. And we now know that nonstandard treatments are not effective and standard treatments are known to be effective. The word that should immediately trigger you is "percentage." Whenever you see the word "percentage" or "proportion," you should immediately check for a percentage v. actual number flaw. The conclusion of the argument depends on the actual amount of money that is being spent on the treatment of disease X because a smaller percentage could still be more money if more money is now being spent on the treatment of disease X.
This is why answer choice (E) is the correct answer: it both strengthens and guarantees the conclusion. It strengthens it because it eliminates the possibility that the overall amount spent on the treatment of disease X has increased. If it had increased, then the conclusion is not necessarily true - even though a decreasing percentage of money is being spent on standard treatments, the total amount of money increasing means that it is not necessarily true that less money is being spent now on effective treatments of disease X than was spent 10 years ago.
Now that we know it strengthens the argument, let's see if it guarantees the conclusion. Let's say that 10 years ago there was $150 total being spent on the treatment of disease X. Let's say originally the money was being split 50-50 for standard and nonstandard methods (i.e. $75 on standard and $75 on nonstandard). Then not only were the percentages changed to 70% spent on nonstandard and 30% spent on standard, but the overall amount decreased to $100, meaning now $70 was spent on nonstandard treatment and $30 was spent on standard treatment. As you can see, having the total money spent on treating disease X slowly decline guarantees that less money is being spent now on effective treatments of disease X than was spent 10 years ago.
Hope this helps! Please let us know if you have any other questions.
CeciOctober 13, 2018
how does E make sense? They didn't stop treating disease X, they just allocated money to the nonstandard one? shouldn't it be D?
MehranOctober 13, 2018
Hi @Ceci. Please re-read the detailed explanation above on this thread. The stimulus presents an argument; the conclusion is about the *total amount* of money spent on effective treatments of disease X, while the premises are about the *percentages* of money spent on effective vs. ineffective treatments of disease X. Answer choice (D) does not strengthen this argument. Rather, as explained in detail just above on this thread, answer choice (E) is the correct answer because it bridges the gap between premises about percentages and a conclusion about total amounts.
