Events & Promotions
|
|
GMAT Club Daily Prep
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
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Apr 2711:00 AM EDT
-12:00 PM EDT
Prefer video-based learning? The Target Test Prep OnDemand course is a one-of-a-kind video masterclass featuring 400 hours of lecture-style teaching by Scott Woodbury-Stewart, founder of Target Test Prep and one of the most accomplished GMAT instructors
Apr 2808:00 AM PDT
-11:00 AM PDT
Whether you are just beginning your MBA journey or fine-tuning your path to a 700+ score, GMAT Day is designed to give you a competitive edge.
30 Aug 2024, 05:06
Kudos
Bookmarks
P0: 5
P20: 43
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
85%
(hard)
Question Stats:
55% (02:36) correct
45%
(02:54)
wrong
based on 539
sessions
History
Date
Time
Result
Not Attempted Yet
Oxygen was being pumped into a tank, and the speed at which the oxygen was being pumped was increasing at a constant, linear rate with respect to time. At the instant the pump was started, time 0 seconds, the oxygen was being pumped at P0 cubic units per second. 20 seconds later, 480 cubic units of oxygen had been pumped into the tank, and the oxygen was being pumped at P20 cubic units per second.
In the table, select values of P0 and P20 that are together consistent with the information provided. Make only two selections, one in each column.
In the table, select values of P0 and P20 that are together consistent with the information provided. Make only two selections, one in each column.
| P0 | P20 | |
| 1 | ||
| 5 | ||
| 25 | ||
| 33 | ||
| 43 | ||
| 51 |
ShowHide Answer
Official Answer
P0: 5
P20: 43
01 Sep 2024, 23:42
Kudos
Bookmarks
There is a shorter method of solving this using an AP.
Let us assume the first term is x and the common difference is the increasing linear rate, i.e., y .
For 0-1 seconds, the rate is x
For 1-2 seconds the rate is x+y
Now, 480 is the sum of the series
Therefore,
Sum of an AP = n/2 (First term + last term)
480 = 20/2 (First term + Last term)
First term + Last term = 48
Hence, find the numbers the sum of which is 48 and y>x.
Let us assume the first term is x and the common difference is the increasing linear rate, i.e., y .
For 0-1 seconds, the rate is x
For 1-2 seconds the rate is x+y
Now, 480 is the sum of the series
Therefore,
Sum of an AP = n/2 (First term + last term)
480 = 20/2 (First term + Last term)
First term + Last term = 48
Hence, find the numbers the sum of which is 48 and y>x.
General Discussion
30 Aug 2024, 08:04
Kudos
Bookmarks
At t=0-1 secs, let's assume O2 is being pumed at x units/sec
Since the rate increases linearly,
At t=1-2 secs, the rate at which O2 is being pumped is say, x+y units/sec
At t=2-3 secs, it's x+2y
...
At t= 19-20 secs, it's x+19y
At the end of 20 secs, a total of 20x + 20*19*y/2 units of oxygen have been pumped. [Using the fomula n*(n+1)/2 for summing a series from 1 to n increasing by 1]
20x + 190y = 480
The only options from the answers that fit this are x = 5, y =2
Therefore at t=0, P0= 5.
At t=20, P20 = 5+19*2= 43.
The question is a bit convulated and I had to make simplifying assumptions to map a linearly increasing rate into concepts that can be solved on the GMAT level. The right concept for this question is setting up an integration equation :/
Since the rate increases linearly,
At t=1-2 secs, the rate at which O2 is being pumped is say, x+y units/sec
At t=2-3 secs, it's x+2y
...
At t= 19-20 secs, it's x+19y
At the end of 20 secs, a total of 20x + 20*19*y/2 units of oxygen have been pumped. [Using the fomula n*(n+1)/2 for summing a series from 1 to n increasing by 1]
20x + 190y = 480
The only options from the answers that fit this are x = 5, y =2
Therefore at t=0, P0= 5.
At t=20, P20 = 5+19*2= 43.
The question is a bit convulated and I had to make simplifying assumptions to map a linearly increasing rate into concepts that can be solved on the GMAT level. The right concept for this question is setting up an integration equation :/
