Railroad spokesperson: Of course it is a difficult task to maintain qu

B is the missing assumption.

E would be correct if this was a strengthen question.

Agree with Zhenmaster - I went for E too but it would strengthen the question we need to find the assumption.
In this case they assume that if people are not satisfied they would not take the train and hence the quality will decline

Hello zhanbo

Can you please confirm my understanding of opton D AND B?

1. option D says It is impossible to reduce subsidies to the railroad network without some effect on the quality of service but we do not know how the effect of subsidy reduction on the quality of rail services ie. positively or negatively . so it can not fill the gap in the argument.

2. i eliminated option B because of the word some. it does not tell how many people 1% or 99% . is it correct to eliminate option only on the basis of one word?

Thanks and regards

The spokesperson's conclusion is "our quality of service has been satisfactory". The spokesperson also states that "the amount of subsidy the taxpayers give the railroad network is reduced“.

The spokesperson is fully convinced of the conclusion. D cannot be the assumption of the spokesperson because
"it is impossible to reduce subsidies to the railroad network without some effect on the quality of service." + ”the amount of subsidy the taxpayers give the railroad network is reduced“
= ”the quality of service“ is adversely affected. This is in direct contradiction with the spokesperson's conclusion. The spokesperson's assumption cannot render the conclusion invalid.

For (B), it has to be assumed to be the case in order to support the spokesperson's conclusion. Because if nobody would refuse to travel by train even if they are not satisfied with the quality of service, the spokesperson cannot adduce the increased ridership to support the conclusion.

(B) is the assumption of the argument, but (B) alone may not be sufficient to fully support the conclusion. The key is: if the assumption is not true, the argument shall fall apart.

Hello ,

My query is related to op a.

Whenever I see 'some', I go for two extreme level cases,

1. Suppose, total passengers be 5 and 'some' can be 1, so 1 out of 5 are dissatisfied by the quality, 25% is a significant number, so we can take this as assumption.

2. Suppose, total passengers be 1000 and 'some' can be 1, hence here 1 out of 1000 are dissatisfied by the quality, which is not significant number, so it can't be taken as assumption.

Please let me know where I am lacking in my understanding.

So this question *seems* to be dealing with something most GMAT questions don't do: sufficient assumptions.

Most assumption questions deal with *necessary* assumptions. The questions are usually, "The author's argument *requires* which of the following?" "Which is an assumption on which the argument depends?"

This question asks which is an assumption the argument is 'based on.' "based on" is somewhat vague language, but it seems to me to lean into 'sufficient' language more than usual.

What's the difference? A necessary assumption must be true, or else the argument is false. A sufficient assumption ensures, or 'locks in' the logic of the argument. There's a lot of overlap and the distinction doesn't often matter, but basically:

NECESSARY ASSUMPTION: if the argument is true, this assumption must be true.

SUFFICIENT ASSUMPTION: if this assumption is true, the argument is guaranteed to be true.

The 'truth' of a necessary assumption isn't actually enough to 'guarantee' the argument (usually because there are *other* necessary assumptions that must also be true for the argument to hold).

Now, B is not actually a sufficient assumption... But it's a necessary consequence of a sufficient assumption! (That's fun).

If we knew that EVERYONE who is dissatisfied with the service DOES NOT RIDE, we would know the author's conclusion is true, because anyone riding would be satisfied and that number has been increasing.

And if EVERYONE who is dissatisfied does not ride, then SOME PEOPLE who are dissatisfied do not ride.

Also, if you negate B, you get 'NO ONE refuses to travel by train if they are dissatisfied with the service,' or, rephrased, 'people who are dissatisfied with the service still ride the train.'

If that's true, the conclusion isn't, I suppose, necessarily *false*, but the reasoning used to support the conclusion falls apart (this is a tricky thing... Usually the 'negation test' reveals a situation that would make the conclusion false. But what the negation test is *really* for is to reveal a situation in which the author's reasoning falls apart... Usually this guarantees a false conclusion, but occasionally it doesn't).

If we learn that 'dissatisfaction doesn't really keep people from riding the train,' the author's points are destroyed. So knowing that some people don't ride the train if they're dissatisfied is a necessary part of the reasoning.

PHEW. That's a pretty unusual question, in very subtle ways.

Mostly, though, this is how I think of the quantifiers:

NONE: 0%
FEW: 10% or less
SOME: 30-50%
ABOUT HALF: ~50%
MOST: 70%
ALMOST ALL: 90% or more

Not a science, or anything.

Thank you Reed.
I had similar situation while answering this one. Once I ignored B by applying GMAT style of answering, if there's one, I lost track.
The highlighted text is where I felt that it is only mentioning what may have been the case afterwards which we aren't concerned off - eventually eliminating it. This led me to find myself in doldrums to choose between C and E. Didn't paid must attention to 'ímprovement' aspect in C and fell for it sadly .

Anyway, great analysis.

isn't "Some people" a lighter word and couldn't be taken as talking about a bunch of people?

In what scenario the quality of service has not been satisfactory,

IF RAIL ROAD NETWORK IS STILL REDUCED INSPITE OF SUBSIDY REDUCTIONS?
BY SUBSIDIY REDUCTION MEANS :

IF INTIALLY THERE WAS A SUBSIDY IN SERVICE OF RS.100/- NOW IT IS 40/-

SO THERE SHOULD BE IMPROVED RAIL ROAD NETWORK