PT1.S3.Q19 - Train Service

moonstars5678

I'm having trouble with these type of logical translation and mapping questions - could someone map out the conditional logic of the stimulus and how the AC fits as the NA?

help

David S.

Hi Moonstars,

Here is the basic breakdown of the argument. Let me stress that you do not need to think of this in formal logic to get to answer choice C, but it might be helpful just for the purpose of thinking about the argument analytically.

P1: Freight AND commuter service --> service neither well

C: Successful business --> focus on one service

Based on the premises, we know that a train service suffers when it offers both freight and commuter service. Servicing both means that the operator can service neither well. Our conclusion, however, is talking about the success of a business (a new and rouge element in this argument). The logical gap between the premises and conclusion is narrow, but there's a distinction between not servicing your customers well and having an unsuccessful business. That gap has to be the argument's assumption, and what we have to target in the answer choices.

There are really only two answer choices that try to bridge the gap and get us to successful business -- C and D. D is far too strong. The argument isn't trying to show that if you just do commuter, that'll guarantee you have a successful business. If anything, the argument is trying to go the other way around. It's saying that in a world where you have a successful business, you for sure only operate one service line.

In formal logic, C fits into the argument this way:

P1: Freight AND commuter service --> NOT service customers well

P2 (AC contrapositive): NOT service customers well --> NOT successful business

C: Freight AND commuter service --> NOT successful
Contrapositive: Successful business --> ONE of either freight or commuter