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555-605 Level|   Math Related|         
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GMAT Club Olympics 2025 (Day 10): A maintenance team estimated that 12 Jul 2025, 04:50
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Bunuel
 


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A maintenance team estimated that a certain pipe pumped 1,300 liters of water into a storage tank in 4 hours. The volume estimate may be off by up to and including 50 liters, and the time estimate may be off by up to and including 0.5 hours.

Select for Minimum the lowest possible actual pumping rate (in liters per hour), and select for Maximum the highest possible actual pumping rate (in liters per hour), consistent with these estimation ranges. Make only two selections, one in each column.
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Estimated rate = 1300/4 liters per hour,

Corrected volume = 1300+50 Liters
Corrected time = 4+0.5 hours

For Minimum possible pumping rate --> Minimum volume pumped in maximum time = (1300-50)/(4+0.5) =1250/4.5


For Maximum possible pumping rate --> Maximum volume pumped in minimum time = (1300+50)/(4-0.5) =1350/3.5
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GMAT Club Olympics 2025 (Day 10): A maintenance team estimated that 12 Jul 2025, 05:05
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Volume range 1250<1300<1350
Time 3.5<4<4.5
Min Rate = Min Volume/Max Time =1250/4.5
Max Rate is Max Volume/Min Time =1350/3.5
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A maintenance team estimated that a certain pipe pumped 1,300 liters of water into a storage tank in 4 hours. The volume estimate may be off by up to and including 50 liters, and the time estimate may be off by up to and including 0.5 hours.

Select for Minimum the lowest possible actual pumping rate (in liters per hour), and select for Maximum the highest possible actual pumping rate (in liters per hour), consistent with these estimation ranges. Make only two selections, one in each column.
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GMAT Club Olympics 2025 (Day 10): A maintenance team estimated that 12 Jul 2025, 05:42
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This question was provided by GMAT Club
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A maintenance team estimated that a certain pipe pumped 1,300 liters of water into a storage tank in 4 hours. The volume estimate may be off by up to and including 50 liters, and the time estimate may be off by up to and including 0.5 hours.

Select for Minimum the lowest possible actual pumping rate (in liters per hour), and select for Maximum the highest possible actual pumping rate (in liters per hour), consistent with these estimation ranges. Make only two selections, one in each column.
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To maximize the pumping rate, the maximum possible value of the water should be in the numerator and minimum possible time should be in the denominator.

To minimize the pumping rate, the minimum possible value of the water should be in the numerator and maximum possible time should be in the denominator.

Maximum:\(\frac{1350}{3.5}\)

Minimum: \(\frac{1250}{4.5}\)
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GMAT Club Olympics 2025 (Day 10): A maintenance team estimated that 12 Jul 2025, 05:58
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The amount of water could be 50 liters more or less, between 1250 and 1350 liters
The time could be 0.5 hours more or less, between 3.5 and 4.5 hours

To get the lowest possible rate, choose as little water as possible (1250 liters) and spread over the longest time possible (4.5 hours): 1250/4.5
To get the highest possible rate, choose as much water as possible (1350 liters) in the shortest time possible (3.5 hours): 1350/3.5

Minimum=1,250/4.5
Maximum=1,350/3.5
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GMAT Club Olympics 2025 (Day 10): A maintenance team estimated that 12 Jul 2025, 06:12
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The volume estimate +/- 50

The time estimate +/- 0.5

Original rate= 1300/4

Minimum: The numerator is the least and the denominator is largest

1250/4.5

Maximum: The numerator is largest and denominator is smallest

1350/3.5
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GMAT Club Olympics 2025 (Day 10): A maintenance team estimated that 12 Jul 2025, 06:13
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1300-50<=V<= 1300+50

1250<=V<=1350

4-0.5<=T<=4+0.5

3.5<=T<=4.5

lowest possible actual pumping rate = Lowest volume of water pumped/Max. time = 1250/4.5
highest possible actual pumping rate = Highest volume of water pumped/Min. time = 1350/3.5
Bunuel
 


This question was provided by GMAT Club
for the GMAT Club Olympics Competition

Win over $30,000 in prizes such as Courses, Tests, Private Tutoring, and more

 



A maintenance team estimated that a certain pipe pumped 1,300 liters of water into a storage tank in 4 hours. The volume estimate may be off by up to and including 50 liters, and the time estimate may be off by up to and including 0.5 hours.

Select for Minimum the lowest possible actual pumping rate (in liters per hour), and select for Maximum the highest possible actual pumping rate (in liters per hour), consistent with these estimation ranges. Make only two selections, one in each column.
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GMAT Club Olympics 2025 (Day 10): A maintenance team estimated that 12 Jul 2025, 06:14
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For the the lowest possible pumping rate, we can pair up smallest volume with longest time
Lowest Vol. = 1,300 – 50 = 1,250 ltrs
Longest Time = 4 + 0.5 = 4.5 hrs
Min = 1,250 / 4.5

For the the highest possible pumping rate, we can pair up largest volume with shortest time
Largest Vol. = 1,300 + 50 = 1,350 ltrs
Shortest Time = 4 - 0.5 = 3.5 hrs
Max = 1,350 / 3.5

Ans : Min = 1,250 / 4.5 ; Max = 1,350 / 3.5
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GMAT Club Olympics 2025 (Day 10): A maintenance team estimated that 12 Jul 2025, 06:16
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volume mistake is of 50 lit so volume can be 1250 lit or 1350 lit.
time estimation error is of 0.5 hrs so correct time can be 3.5 hrs or 4.5 hrs
so, minimum possible actual pumping rate = 1250/4.5
and maximum possible actual pumping rate = 1350/3.5
Bunuel
 


This question was provided by GMAT Club
for the GMAT Club Olympics Competition

Win over $30,000 in prizes such as Courses, Tests, Private Tutoring, and more

 



A maintenance team estimated that a certain pipe pumped 1,300 liters of water into a storage tank in 4 hours. The volume estimate may be off by up to and including 50 liters, and the time estimate may be off by up to and including 0.5 hours.

Select for Minimum the lowest possible actual pumping rate (in liters per hour), and select for Maximum the highest possible actual pumping rate (in liters per hour), consistent with these estimation ranges. Make only two selections, one in each column.
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GMAT Club Olympics 2025 (Day 10): A maintenance team estimated that 12 Jul 2025, 06:17
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Option E and Option B are our answers.

Lets understand the information mention in the question first before trying to solve the question.

So the question starts by telling us that "A maintenance team estimated that a certain pipe pumped 1,300 liters of water into a storage tank in 4 hours. The volume estimate may be off by up to and including 50 liters, and the time estimate may be off by up to and including 0.5 hours". And asks us "the lowest possible actual pumping rate" & "highest possible actual pumping rate".

Now as per the information mentioned in question the estimated pumping rate of the piper is 1300 liter which could be off by ±50 liter then it tells us that it took 4 hours to fill the tank and th time could also be off by ±0.5 hours.

Form here the estimated rate with the given numbers will be: Rate = Work/Time => Rate = 1300/4 => Rate = 325 liter.

Now in order to answer the first part of the question i.e. lowest possible actual pumping rate to answer this we need to minimize the work and maximize the time take for that work. The question tells us that the work is off by ±50 liter and time is off by ±0.5 hours.

So the maximum possible time will be 4.5 hours and the minimum possible work will be 1250 liter.
For this we can tell that the minimum possible rate = 1250/4.5 => 277.77 liter (Option E)

Now in order to answer the first part of the question i.e. highest possible actual pumping rate to answer this we need to maximize the work and minimize the time needed to do that work. The question tells us that the work is off by ±50 liter and time is off by ±0.5 hours.

So the time will be 3.5 hours and the work will be 1350 liter.
For this we can tell that the maximum possible rate = 1350/3.5 => liter (Option B)


So from here we can conclude that Option E and Option B are our answers.


Bunuel
 


This question was provided by GMAT Club
for the GMAT Club Olympics Competition

Win over $30,000 in prizes such as Courses, Tests, Private Tutoring, and more

 



A maintenance team estimated that a certain pipe pumped 1,300 liters of water into a storage tank in 4 hours. The volume estimate may be off by up to and including 50 liters, and the time estimate may be off by up to and including 0.5 hours.

Select for Minimum the lowest possible actual pumping rate (in liters per hour), and select for Maximum the highest possible actual pumping rate (in liters per hour), consistent with these estimation ranges. Make only two selections, one in each column.
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GMAT Club Olympics 2025 (Day 10): A maintenance team estimated that 12 Jul 2025, 06:29
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Work (Water volume) = 1300 liters
Work (Volume estimate) : Maximum = 1300 + 50 = 1350 liters & Minimum = 1300 - 50 = 1250 liters
Time = 4 Hours
Time estimate : Maximum = 4 + 0.5 = 4.5 Hrs. & Minimum = 4 - 0.5 = 3.5 Hrs.

So, lowest possible actual pumping rate (in liters per hour) is when our work (Water pumped) is minimum and time (time taken to fill the tank) is maximum i.e., Work = 1250 liters and time taken = 4.5 Hrs.
Lowest possible rate = 1250/ 4.5 = 2500 / 9 = 1250 / 4.5 liters/ Hr.

And the maximum possible actual pumping rate (in liters per hour) is when our work (Water pumped) is maximum and time (time taken to fill the tank) is minimum i.e., Work = 1350 liters and time taken = 3.5 Hrs.
Lowest possible rate = 1350/ 3.5 = 2700 / 7 = 1350 / 3.5 liters/ Hr.
Bunuel
 


This question was provided by GMAT Club
for the GMAT Club Olympics Competition

Win over $30,000 in prizes such as Courses, Tests, Private Tutoring, and more

 



A maintenance team estimated that a certain pipe pumped 1,300 liters of water into a storage tank in 4 hours. The volume estimate may be off by up to and including 50 liters, and the time estimate may be off by up to and including 0.5 hours.

Select for Minimum the lowest possible actual pumping rate (in liters per hour), and select for Maximum the highest possible actual pumping rate (in liters per hour), consistent with these estimation ranges. Make only two selections, one in each column.
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GMAT Club Olympics 2025 (Day 10): A maintenance team estimated that 12 Jul 2025, 06:46
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For lowest possible pumping rate when minimum work is done in maximum time ie;
1250 liters in 4.5 hours
So rate will be 1250 liters/4.5 hours
Hence select 1250/4.5 For Minimum

For highest possible pumping rate when maximum work done in minimum time ie;
1350 liters in 3.5 hours
So rate will be 1350 liters/3.5 hours
Hence select 1350/3.5 For Maximum
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GMAT Club Olympics 2025 (Day 10): A maintenance team estimated that 12 Jul 2025, 07:05
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V=1300
T=4 hrs
R=V/T
To min and max V can be 1250-1350 and T =3.5-4.5 hours
Min R=1250/4.5
Max R =1350/3.5
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GMAT Club Olympics 2025 (Day 10): A maintenance team estimated that 12 Jul 2025, 07:13
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1300-50=1250 <= volume <= 1300+50=1350
4-0.5=3.5 <= time <= 4+0.5=4.5

rate=volume/time

To minimize rate, use lowest volume and use highest time = 1250/4.5
To maximize rate, use highest volume and use lowest time = 1350/3.5

Correct answers: Minimum=1,250/4.5 and Maximum=1,350/3.5
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GMAT Club Olympics 2025 (Day 10): A maintenance team estimated that 12 Jul 2025, 07:14
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Quantity range is +/-50 = 1300-50 to 1300+50 >> 1250 to 1350
Hours range is +/- 0.5 = 4-0.5 to 4+0.5 >> 3.5 to 4.5

We will get Minimum range when we divide the minimum quantity by maximum hours = 1250/4.5

We will get maximum range when we divide maximum quantity by minimum hours = 1350/3.5
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GMAT Club Olympics 2025 (Day 10): A maintenance team estimated that 12 Jul 2025, 07:27
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volume can be between 1250 and 1350
time can be between 3.5 and 4.5

volume/time will be minimum when volume is the least possible value and time the greatest possible value: 1250/4.5
volume/time will be maximun when volume is the greatest possible value and time the least possible value: 1350/3.5

The right answers:
Minimum=1,250/4.5
Maximum=1,350/3.5
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GMAT Club Olympics 2025 (Day 10): A maintenance team estimated that 12 Jul 2025, 07:35
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Minimum possible pumping rate when the volume is as small as possible and the time is as large as possible: (1300-50)/(4+0.5) = 1250/4.5
Maximum possible pumping rate when the volume is as large as possible and the time is as small as possible: (1300+50)/(4-0.5) = 1350/3.5

Minimum=1,250/4.5 and Maximum=1,350/3.5
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GMAT Club Olympics 2025 (Day 10): A maintenance team estimated that 12 Jul 2025, 07:41
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Rate is in -> Liters of water filled/number of hours

To maximize the rate, maximize the numerator and minimize the denominator.
Maximum water that can be filled = 1350 Liters
Minimum time that can be taken = 3.5 hours
Max pumping rate = 1350/3.5

To minimize the rate, minimize the numerator and maximize the denominator.
Minimum water that can be filled = 1250 Liters
Maximum time that can be taken = 4.5 hours
Min pupming rate = 1250/4.5
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