A Tricky DS

This topic has expert replies
Junior | Next Rank: 30 Posts
Posts: 10
Joined: Fri Apr 25, 2014 10:27 pm

A Tricky DS

by itzmyzone911 » Sat Oct 04, 2014 3:27 am
A review website accords 'ratings' to a product by recording the percentage of customers who have reported their views as either 'satisfied' or 'unsatisfied' only. Using the given data from the website, is the LEAST possible total number of people that could have reported their views greater than 10?

1. The website rounds off the exact percentage value calculated to the closest integral value.
2. The percentage of people reported in the data as 'unsatisfied' when rounded off to the nearest integer is 67%.

[spoiler]OA:C[/spoiler]
Last edited by itzmyzone911 on Sat Oct 04, 2014 7:22 pm, edited 1 time in total.

GMAT/MBA Expert

User avatar
Elite Legendary Member
Posts: 10392
Joined: Sun Jun 23, 2013 6:38 pm
Location: Palo Alto, CA
Thanked: 2867 times
Followed by:511 members
GMAT Score:800

by [email protected] » Sat Oct 04, 2014 11:10 am
Hi itzmyzone911,

What is the source of this question? I ask because I don't that the "intent" of the prompt matches the wording of the prompt. Here's the problem:

The question asks "is the LEAST POSSIBLE total number of people...greater than 10?"

The information in both Facts leads us to a definitive NO answer. Assuming that there were a certain number of Satisfied customers and a certain number of Unsatisfied customers, the minimum number of people would be 2 (1 of each type). Fact 1 doesn't do anything to counter that point. Fact 2 does a little (but we could have 3 customers - 2 Unsatisfied, 1 Satisfied - which matches the rounded 67%), but we would still have a definitive NO.

The "intent" is probably meant to ask something akin to "what IS the number of people who reported their views?", but that's a different question altogether. The given answer does not match the prompt (as is). This prompt wouldn't appear as a scored item on the GMAT and I would be suspicious of the source.

GMAT assassins aren't born, they're made,
Rich
Contact Rich at [email protected]
Image

Junior | Next Rank: 30 Posts
Posts: 10
Joined: Fri Apr 25, 2014 10:27 pm

by itzmyzone911 » Sat Oct 04, 2014 12:09 pm
Hi Rich,

My take on the question..

The last sentence of the question reads 'USING THE GIVEN DATA FROM THE WEBSITE, is the least...?'. Only once WE ARE GIVEN some data from the website, we are supposed to start speculating the least possible no. of respondents. The main question does not provide any such data, leaving us to seek some data from the Facts (1 and 2) provided in order to enable us answer the problem.
If one were to start assuming values without carefully reading the 1st half of the last sentence, then one would end up answering the question (a definite NO) even without having to read the Facts given, leading us to an option F (The data in the stimulus itself is sufficient to answer the question asked. Neither 1 or 2 is needed)

1. Gives no information about data obtained from website on basis of which the required qty. can be speculated...Insufficient
2. Gives us some information, albeit a distorted one, saying that the data GIVEN FROM THE WEBSITE ONLY IF rounded off to the nearest integer would yield 67%. This means that that there are infinite possible values actually obtainable from the data ranging from 66.51% to 67.49%, each having its own value of denominator (when expressed as a fraction in the most-reduced form) equal to the qty. required....Insufficient

Only after combining can one speculate that from the entire range of 66.51% to 67.49%, the value of 66.6% shall yield the lowest possible figure of 3 (2/3) as the required qty. Hence a definite NO, answer C.

Shall be glad to know your thoughts..

GMAT Instructor
Posts: 2630
Joined: Wed Sep 12, 2012 3:32 pm
Location: East Bay all the way
Thanked: 625 times
Followed by:119 members
GMAT Score:780

by Matt@VeritasPrep » Sun Oct 12, 2014 10:29 pm
The question is not clearly worded and the OA is wrong. There's nothing in S1 that isn't in S2 -- "rounded off to the nearest integer" is no different from "rounds off ... to the closest integral value" -- so the answer is either B or E. Given S2 we have the possibility of 2 unsatisfied people out of 3 total participants. The total could NOT have been 0 people, 1 person, or 2 people, as those would give percentages of 0%, 50%, or 100%, depending on the case, none of which rounds to 67%. If you accept a lot of speculation, the least possible total is 3, and the answer is B.

If you don't accept that much speculation, and believe that a proper integral ratio must be found before a minimum total can be suggested, then the answer is E: 2/3 could be the ratio, but so could 668/1000, which would give a different minimum.

That said, the ambiguous grammar and strange inconsistencies in this question make it hard to see exactly what's asked for and what's given, at least without making assumptions the GMAT would never require us to make. I'm guessing you wrote it, so I'd recommend that you iron out some of these issues before putting it on a CAT or a website.