Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.
Customized for You
we will pick new questions that match your level based on your Timer History
Track Your Progress
every week, we’ll send you an estimated GMAT score based on your performance
Practice Pays
we will pick new questions that match your level based on your Timer History
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
It appears that you are browsing the GMAT Club forum unregistered!
Signing up is free, quick, and confidential.
Join other 500,000 members and get the full benefits of GMAT Club
Registration gives you:
Tests
Take 11 tests and quizzes from GMAT Club and leading GMAT prep companies such as Manhattan GMAT,
Knewton, and others. All are free for GMAT Club members.
Applicant Stats
View detailed applicant stats such as GPA, GMAT score, work experience, location, application
status, and more
Books/Downloads
Download thousands of study notes,
question collections, GMAT Club’s
Grammar and Math books.
All are free!
Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:
At a certain hospital, 75% of the interns receive fewer than [#permalink]
06 Dec 2008, 06:02
This topic is locked. If you want to discuss this question please re-post it in the respective forum.
At a certain hospital, 75% of the interns receive fewer than 6 hours of sleep and report feeling tired during their shifts. At the same time, 70% of the interns who receive 6 or more hours of sleep report no feelings of tiredness. If 80% of the interns receive fewer than 6 hours of sleep, what percent of the interns report no feelings of tiredness during their shifts? _________________
My Guess us 75 %. Here is the explanation. I tried putting the given data in a 3 X 3 table format. First row is % pfeeling tired, second row - Not feeling tired, third row - Total % of people having > or < 6 hrs sleep.
Similarly First column is % of people getting fewer than 6 hrs,of sleep, second column is % of people getting >- 6 hrs of sleep, third column is total % of being tired or not tired. The one black are given in the question. And the one in Blue are derived.
The answer is actually 19% Like the last poster I advocate using a 3X3 grid to solve all of these problems. Since this is hard to do online, I'll give write it out.
To begin, let's say there are 100 interns. So, now we are looking for the number of interns who report no feelings of tiredness. This means there are two groups we are interested in: 1) Interns with fewer than 6 hours sleep who are not tired and 2) Interns with 6+ hours sleep who are not tired. We'll handle each case separately. 1) We are told that 80 of the interns receive fewer than 6 hours of sleep, and 75 of the interns receive fewer than 6 hours of sleep and report tiredness. This means that 5 of all interns receive fewer than 6 hours of sleep and aren't tired.
2) If 80 of the interns receive fewer than 6 hours of sleep, then 20 of interns get more than 6 hours of sleep. Of the 20 interns that get more than 6 hours sleep, we are told that 70% of them report no feelings of tiredness. This means that 14 interns get 6+ hours sleep and aren't tired.
5% of interns (80% minus 75%) report no tiredness 14% of interns (70% of 20%) report no tiredness
19%
fairly tricky, I started out confused over 75% of the 80% of interns, but it was 75% of the 100%, had to read a couple times. GMAT is all about tricks.
I agree that the ans is 19%. I miscalculated the values for the interns who got 6 hrs or more sleep. Well need to reread the questions couple of more times I guess.