LSAT 108 | Section 2 | Logical Reasoning: Q15

LR Question 15 Explanation

QUESTION TEXT: Each of two drugs, S and T, greatly …

QUESTION TYPE: Necessary Assumption

CONCLUSION: Society has to decide whether to pay $240,000 to save one extra patient by using drug T instead of drug S.

REASONING:

• Both drugs reduce the effects of serious heart attacks.
• Drug T saves 1 extra life per 120 treatments compared with drug S.
• Drug T costs $2,000 more per treatment.

ANALYSIS: The math is essentially: treating 120 people with T costs 120 × $2,000 more = $240,000 more and saves 1 extra life.

Why do we have to choose the same drug for everyone? The argument gives us a dichotomy: either choose T or S.

But what if doctors could cheaply and quickly tell which patients actually need T? Then society wouldn’t face the stark choice of paying $240,000 extra across 120 patients. It could just give T to the specific patients for whom S wouldn’t work as well.

So the argument needs to assume there’s no practical way to identify those cases ahead of time. If there was a way, the conclusion that we have to choose one path to go down makes no sense.

___________

1. Even if S has side effects that T doesn’t, the argument is only framing a cost-per-life-saved question. Side effects might be another reason to prefer T, but the argument doesn’t rely on them.
2. Development costs explain why T may be expensive, but they don’t affect whether society faces this policy choice. The argument works regardless of why T costs more.
3. This would make T even more attractive, but the argument never assumes T has this additional advantage. The extra life saved could occur for entirely different reasons.
4. CORRECT. If there’s no quick, practical, inexpensive way to tell which patients need T, then society really does face an all-or-nothing decision: pay an extra $240,000 across 120 treatments to save one additional life.
   Negation: There is a quick, easy, and cheap way to tell whether drug S will be as effective as drug T for a given patient.
5. T doesn’t have to work faster for the argument to go through. We’re already told both drugs are effective when administered as soon as possible after the heart attack begins.