Certain instruments used in veterinary surgery can be made either of stainless steel or of nylon. In a study of such ...

on August 10, 2019

Explanation

Can someone walk me through why B cannot be true? Thanks!

Replies

Irina on August 10, 2019

@Minerva,

Let's look at the argument:

Certain instruments used in veterinary surgery can be made either of stainless steel or nylon. In a study of such instruments, 50 sterilizations of a nylon set required 3.4 times the amount of energy used to manufacture that set, whereas 50 sterilizations of stainless steel required 2.1 times the energy.

Which of the following statements CANNOT be true?

(B) says "More energy was required for each complete sterilization of the nylon instruments that was required to manufacture the nylon instruments."

If that were the case, 50 sterilizations would require 50+ times the energy used to manufacture, not merely 3.4 times.

Does that make sense?

Let me know if you have any further questions.

Amar on October 25, 2019

hello, why would c cannot be true?

on May 10, 2021

I have the same question. Could someone please explain C?

Garrett on July 11 at 07:20PM

You guys really have not responded to a question from 2019.. seriously?

Mazen on November 19 at 11:43PM

Hi,

I am not a tutor, but I can help.

C can be true and should therefore be eliminated. The question is "could be true EXCEPT"; therefore, it follows that four of the answer choices are wrong because they could be true, and one - the exception - cannot be true and is the correct answer.

C compares the number of nylon instruments in a set to the number of stainless steel instruments in a set. We cannot infer anything about the sets between the nylon and the stainless steel because the stimulus does not connect the two materials in any way.

Note that the stimulus compares the energy required to clean a specific material to energy required to manufacture that very same material. So it is cleaning nylon to manufacturing nylon; and cleaning stainless steel to manufacturing stainless steel. But we now nothing insofar as nylon to stainless steel!

In retrospect, any answer choices inferring a relationship between the nylon against the stainless steel are highly speculative and precluding us from inferring a comparative statement between them. This knocks out A, C, D and E.

B, in the context of the stimulus, is mathematically impossible, or cannot be true, and is therefore the correct answer: if B - "[m]ore energy was required for *each* complete sterilization of the nylon instruments than was required to manufacture the nylon instruments" - is correct, then the math would add up to more than 50 times, not 3.4 times per the stimulus, for the total 50 complete sterilizations.
For example: manufacturing one set of nylon-made instruments takes 1000 units of energy.
Sterilizing that very same set 50 times, per the stimulus would require 1000*3.4=3400 units
So the amount of energy per one sterilization would take 3400 divided by 50 = 68 units of energy.
68 units of energy to execute one sterilization is less than 1000 units of energy required to manufacture that same instrument. But B states the reverse: "More energy was required for [EACH] complete [STERILIZATION] of the nylon instruments [THAN] was required to [MANUFACTURE] the nylon instruments.

Having analyzed all this, honestly, I think the objective of the LSAT writers in this question is to test our ability to select the answer through the process of elimination. I think that because directly proving B requires some basic math, which no unreasonable, but unusual for the LSAT writers to test for based on my experience!

Again I am not a tutor, but that's what I got from this question.

Mazen