Cofocor wrote:
Thank you very much for your fast response Mike, point taken.
Just to highlight that the numbers were only examples to support the rational behind the claim.
If in 2015 the members were 100 and in 2016 MORE than 250 join the gym (700) and we take the negative of the statement E: MORE than 250 ended their membership in 2016 (350), the argument still remains valid although the statement E is false (the membership has risen significantly, in this case from 100 to 450: 100+700-350=450). If E is true or false the argument remains valid, cannot be the assumption in which the argument relies.
I think that removing the "MORE" in the argument the solution will be then clearly E.
Thank you Mike.
Dear
Cofocor,
I'm happy to respond.
My friend, you are still thinking of this as the way math problems are phrased rather than the way people actually speak in the real world. The GMAT CR, even the ones that mention something numerical, reflect the way real business people talk. It is a profound mistake to read them as if they were math problems.
Here's the prompt again.
Egidio's Gym has been in operation for seven years, and offers regular weekly weight training and aerobic classes, as well as occasional programs in dance and martial arts. The gym has seen a surge of new members in the past twelve months, despite keeping the same membership fee over the past three years. Of the 450 current members, more than 250 have joined in the past year. Clearly, the membership of Egidio's Gym has risen a significant amount because of its superior facilities.Note that the total is 450, so that's one constraint by which we should abide.
Here is the distinction I want to make.
If a math problem says, "
X is greater than 250," then X could be any number on the number line above 250. Even given the integer constraint and the cap of 450, X could be any of the two hundred positive integers from 251 to 450. Moreover, no one of those numbers would be any more likely than any other.
That's how mathematicians talk in math problems. That's not how business people talk in the real world.
This argument is presumably being made by some spokesperson or marketing person for Egidio's Gym. If I want to make the point about how many new members have joined, I am mostly likely going to use a close round number that is very near to the real number. I would say that, from the statement, it's likely that that the number of new members is between 250 and 260, perhaps in the low 260s. Think about it: if 287 were the number of new members just joined, the spokesperson would be wildly undercutting his own argument to say "
more than 250"---he would be be more likely to say something like "
more than 280" because he is trying to make a point about the size of this group. For this person to underestimate the size of this group would weaken his own argument.
You see, we have to assume that
all the arguments in the GMAT CR are made in good faith. Part of what this means is that we have to assume that all the factual data cited, all the premises, are simply true. We also have to assume that the speaker is an intelligent competent person with consistent motivations. We have to assume that the person has a point to make and is not intentionally a self-weakener. If the motivation of this spokesperson is to demonstrate how many new members are joining Egidio's gym, then this person would have absolutely no reason to understate the number he cites, except maybe to round it down to a multiple of ten for simplicity (a lot of people out there are particularly fond of multiples of ten, a phenomenon most perplexing to the true mathematicians.) In this context, "
more than 250" would quite likely mean a value below 260.
Now, on the surface, the prompt seems to present a valid argument. More than 50% of the members have joined in the past year. If no one left the gym, and the entire increase could be attributed to new members joining, this scenario would be mean that Egidio's gym grew by more than 100% in a year. That's very impressive growth! That's what the speaker of the argument wants us to believe.
Now, look at the negation of (E)
More than 250 members ended their membership at Egidio's Gym over the last year.
Let's say that 258 joined and 251 left. That's a gain of 7 members, and 7 of 450 is less than a 2% increase. That's pathetic growth. Of course, if the number that left was larger than the number that joined, then there's no increase at all. Anything that demonstrates that the growth was pathetically small or non-existent would obliterate the argument that was predicated on spectacular growth.
I think you are imagining much more mathematical wiggle room because you are not thinking of this in terms of what a real person in the business world would say. That right there is the entire point of the GMAT CR. The GMAT has a CR section so that they can get a sense of how students would handle arguments in the real world.
Does all this make sense?
SanjayaGupta wrote:
I have a query regarding the ans option E.
If you negate the assumption it should break the conclusion. But in this case, it will strengthen the conclusion. Could someone clarify on this.
Dear
SanjayaGupta,
I'm happy to respond.
I explained in this post the logic of the question and how the negation of (E) is a powerful weakener. If you do not agree, I will challenge you to explain how you think the negation of (E) strengthens the argument.
Does this make sense?
Mike
_________________
Mike McGarry
Magoosh Test PrepEducation is not the filling of a pail, but the lighting of a fire. — William Butler Yeats (1865 – 1939)