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.
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:
53% (02:32) correct 47% (03:07) wrong based on 207 sessions
HideShow timer Statistics
It takes printer A 4 more minutes than printer B to print 40 pages. If working together, the two printers can print 50 pages in 6 minutes, how long will it take printer A to print 80 pages?
It takes printer A 4 more minutes than printer B to print 40 pages. If working together, the two printers can print 50 pages in 6 minutes, how long will it take printer A to print 80 pages?
A. 12 B. 18 C. 20 D. 24 E. 30
Let the time needed to print 40 pages for printer A be \(a\) minutes, so for printer B it would be \(a-4\) minutes.
The rate of A would be \(rate=\frac{job}{time}=\frac{40}{a}\) pages per minute and the rate of B \(rate=\frac{job}{time}=\frac{40}{a-4}\) pages per minute.
Their combined rate would be \(\frac{40}{a}+\frac{40}{a-4}\) pages per minute. Also as "two printers can print 50 pages in 6 minutes" then their combined rate is \(rate=\frac{job}{time}=\frac{50}{6}\), so \(\frac{40}{a}+\frac{40}{a-4}=\frac{50}{6}\).
\(\frac{40}{a}+\frac{40}{a-4}=\frac{50}{6}\). Divide by 40: \(\frac{1}{a}+\frac{1}{a-4}=\frac{5}{24}\). At this point we can either try to substitute the values from answer choices or solve quadratic equation. Remember as we are asked to find the time needed for printer A to print \(80\) pages, then the answer would be \(2a\) (as \(a\) is the time needed to print \(40\) pages).
It takes printer A 4 more minutes than printer B to print 40 pages. If working together, the two printers can print 50 pages in 6 minutes, how long will it take printer A to print 80 pages?
A. 12 B. 18 C. 20 D. 24 E. 30
Let the time needed to print 40 pages for printer A be \(a\) minutes, so for printer B it would be \(a-4\) minutes.
The rate of A would be \(rate=\frac{job}{time}=\frac{40}{a}\) pages per minute and the rate of B \(rate=\frac{job}{time}=\frac{40}{a-4}\) pages per minute.
Their combined rate would be \(\frac{40}{a}+\frac{40}{a-4}\) pages per minute. Also as "two printers can print 50 pages in 6 minutes" then their combined rate is \(rate=\frac{job}{time}=\frac{50}{6}\), so \(\frac{40}{a}+\frac{40}{a-4}=\frac{50}{6}\).
\(\frac{40}{a}+\frac{40}{a-4}=\frac{50}{6}\). Divide by 40: \(\frac{1}{a}+\frac{1}{a-4}=\frac{5}{24}\). At this point we can either try to substitute the values from answer choices or solve quadratic equation. Remember as we are asked to find the time needed for printer A to print \(80\) pages, then the answer would be \(2a\) (as \(a\) is the time needed to print \(40\) pages).
Answer D works:
\(2a=24\);
\(a=12\);
\(\frac{1}{12}+\frac{1}{8}=\frac{5}{24}\).
Answer: D
I tried to solve this question by considering time taken by B as "a" and that by printer A as "a+4" but was unable to solve the question. Why should B's time be "a" and A's time be "a-4" and not the other way around?
It takes printer A 4 more minutes than printer B to print 40 pages. If working together, the two printers can print 50 pages in 6 minutes, how long will it take printer A to print 80 pages?
A. 12 B. 18 C. 20 D. 24 E. 30
Let the time needed to print 40 pages for printer A be \(a\) minutes, so for printer B it would be \(a-4\) minutes.
The rate of A would be \(rate=\frac{job}{time}=\frac{40}{a}\) pages per minute and the rate of B \(rate=\frac{job}{time}=\frac{40}{a-4}\) pages per minute.
Their combined rate would be \(\frac{40}{a}+\frac{40}{a-4}\) pages per minute. Also as "two printers can print 50 pages in 6 minutes" then their combined rate is \(rate=\frac{job}{time}=\frac{50}{6}\), so \(\frac{40}{a}+\frac{40}{a-4}=\frac{50}{6}\).
\(\frac{40}{a}+\frac{40}{a-4}=\frac{50}{6}\). Divide by 40: \(\frac{1}{a}+\frac{1}{a-4}=\frac{5}{24}\). At this point we can either try to substitute the values from answer choices or solve quadratic equation. Remember as we are asked to find the time needed for printer A to print \(80\) pages, then the answer would be \(2a\) (as \(a\) is the time needed to print \(40\) pages).
Answer D works:
\(2a=24\);
\(a=12\);
\(\frac{1}{12}+\frac{1}{8}=\frac{5}{24}\).
Answer: D
I tried to solve this question by considering time taken by B as "a" and that by printer A as "a+4" but was unable to solve the question. Why should B's time be "a" and A's time be "a-4" and not the other way around?
hi, printer A= a, B=a-4.. OR printer B=a and A= a+4..
both the above cases are same and if you have taken the second case, be careful in that you are getting a as value of B and you will have to convert to A's time.. You could be going wrong there, otherwise you should get the answer either way _________________
It takes printer A 4 more minutes than printer B to print 40 pages. If working together, the two printers can print 50 pages in 6 minutes, how long will it take printer A to print 80 pages?
A. 12 B. 18 C. 20 D. 24 E. 30
Let the time needed to print 40 pages for printer A be \(a\) minutes, so for printer B it would be \(a-4\) minutes.
The rate of A would be \(rate=\frac{job}{time}=\frac{40}{a}\) pages per minute and the rate of B \(rate=\frac{job}{time}=\frac{40}{a-4}\) pages per minute.
Their combined rate would be \(\frac{40}{a}+\frac{40}{a-4}\) pages per minute. Also as "two printers can print 50 pages in 6 minutes" then their combined rate is \(rate=\frac{job}{time}=\frac{50}{6}\), so \(\frac{40}{a}+\frac{40}{a-4}=\frac{50}{6}\).
\(\frac{40}{a}+\frac{40}{a-4}=\frac{50}{6}\). Divide by 40: \(\frac{1}{a}+\frac{1}{a-4}=\frac{5}{24}\). At this point we can either try to substitute the values from answer choices or solve quadratic equation. Remember as we are asked to find the time needed for printer A to print \(80\) pages, then the answer would be \(2a\) (as \(a\) is the time needed to print \(40\) pages).
Answer D works:
\(2a=24\);
\(a=12\);
\(\frac{1}{12}+\frac{1}{8}=\frac{5}{24}\).
Answer: D
why do we have to take 40/a+40/a−4 and not 40/a+40/a+4 why is my answer not coming right?
It takes printer A 4 more minutes than printer B to print 40 pages. If working together, the two printers can print 50 pages in 6 minutes, how long will it take printer A to print 80 pages?
A. 12 B. 18 C. 20 D. 24 E. 30
Let the time needed to print 40 pages for printer A be \(a\) minutes, so for printer B it would be \(a-4\) minutes.
The rate of A would be \(rate=\frac{job}{time}=\frac{40}{a}\) pages per minute and the rate of B \(rate=\frac{job}{time}=\frac{40}{a-4}\) pages per minute.
Their combined rate would be \(\frac{40}{a}+\frac{40}{a-4}\) pages per minute. Also as "two printers can print 50 pages in 6 minutes" then their combined rate is \(rate=\frac{job}{time}=\frac{50}{6}\), so \(\frac{40}{a}+\frac{40}{a-4}=\frac{50}{6}\).
\(\frac{40}{a}+\frac{40}{a-4}=\frac{50}{6}\). Divide by 40: \(\frac{1}{a}+\frac{1}{a-4}=\frac{5}{24}\). At this point we can either try to substitute the values from answer choices or solve quadratic equation. Remember as we are asked to find the time needed for printer A to print \(80\) pages, then the answer would be \(2a\) (as \(a\) is the time needed to print \(40\) pages).
Answer D works:
\(2a=24\);
\(a=12\);
\(\frac{1}{12}+\frac{1}{8}=\frac{5}{24}\).
Answer: D
why do we have to take 40/a+40/a−4 and not 40/a+40/a+4 why is my answer not coming right?
Please check the discussion above. For example, this post: m17-184126.html#p1663300 _________________
It takes printer A 4 more minutes than printer B to print 40 pages. If working together, the two printers can print 50 pages in 6 minutes, how long will it take printer A to print 80 pages?
A. 12 B. 18 C. 20 D. 24 E. 30
Let the time needed to print 40 pages for printer A be \(a\) minutes, so for printer B it would be \(a-4\) minutes.
The rate of A would be \(rate=\frac{job}{time}=\frac{40}{a}\) pages per minute and the rate of B \(rate=\frac{job}{time}=\frac{40}{a-4}\) pages per minute.
Their combined rate would be \(\frac{40}{a}+\frac{40}{a-4}\) pages per minute. Also as "two printers can print 50 pages in 6 minutes" then their combined rate is \(rate=\frac{job}{time}=\frac{50}{6}\), so \(\frac{40}{a}+\frac{40}{a-4}=\frac{50}{6}\).
\(\frac{40}{a}+\frac{40}{a-4}=\frac{50}{6}\). Divide by 40: \(\frac{1}{a}+\frac{1}{a-4}=\frac{5}{24}\). At this point we can either try to substitute the values from answer choices or solve quadratic equation. Remember as we are asked to find the time needed for printer A to print \(80\) pages, then the answer would be \(2a\) (as \(a\) is the time needed to print \(40\) pages).
Answer D works:
\(2a=24\);
\(a=12\);
\(\frac{1}{12}+\frac{1}{8}=\frac{5}{24}\).
Answer: D
why do we have to take 40/a+40/a−4 and not 40/a+40/a+4 why is my answer not coming right?
It takes printer A 4 more minutes than printer B to print 40 pages. If working together, the two printers can print 50 pages in 6 minutes, how long will it take printer A to print 80 pages?
A. 12 B. 18 C. 20 D. 24 E. 30
I like the solution when after we get to 1/a+1/(a−4)=5/24, we check the answer choices.
I solved the full quadr equation: 50/ (40/(t+4) + 40/t) = 6 - got pretty big numbers and although i solved it correct, it took me over 4 minutes, which is unacceptable. (We have to find 2t+8 in this case).
But then I realized, that we can simplify this equation. It takes printer A 4 more minutes than printer B to print 40 pages = It takes printer A 1 more minute than printer B to print 10 pages In this case we have to solve next equation: 50/(10/(t+1) + 10/t) = 6 (and to find 2t+8)- this is much faster than the first one.
Let's assume that both of them are the same printers and let's replace 40 pages by 50 pages. Together they printed 50 pages in 6 minutes. It means that 1 printer can print 50 pages in 12 minutes. 12 minutes - our average time taken by both different printers. Given that A is slower than B for 4 minutes, the only values we can get are 10 and 14 minutes (average is 12, and one is more gradual than another for 4 minutes).
Printer A can print 50 pages in 14 minutes and 100 pages in 28 minutes. Therefore, it can print 80 pages a little bit faster than 28 minutes. Answer - 24 minutes. Confidence - 80%. Time - about 1 minute
close
53% (02:32) correct 
