Two water storage tanks, Tank A and Tank B, can each hold more than 20

Question

Two water storage tanks, Tank A and Tank B, can each hold more than 20,000 liters of water. Currently, Tank A contains 5,000 liters of water, while Tank B contains 8,000 liters. Each tank is being filled at a constant rate, such that in 15 hours, the two tanks will contain the same amount of water, though neither will be full.

In the table below, identify rates of filling for each tank that are together consistent with the information. Make only one selection in each column.

In the table below, identify rates of filling for each tank that are together consistent with the information. Make only one selection in each column.

GmatTest2026 · Accepted Answer

Solution:

Tank A contains 5,000 liters of water and Tank B contains 8000 liters of water.

Each tank works at a constant rate and in 15 hours both tanks have the same amount of water. So, let's assume the rate of tank A is X and the rate of tank B is Y and we will set up an equation.

5000 + 15X = 8000 + 15Y

15X = 3000 + 15Y

15X - 15Y = 3000

X - Y = 200 and look into the option and we will have the value for X = 290 and Y = 90

MuskaanMittal · Answer

Calculate the total litres with each rate - as the two tanks are filling for 15 hours. multiply each rate with 15.
30L/h = 450L
90L/h = 1350L
150L/h = 2250L
220L/h = 3300L
290L/h = 4350L

Use hit and trail method and add maximum litres to tank A and minimum to tank B (because B has more litres already, it will require less amount to be added to come equal to A)

Therefore, 5000+4350 = 9350 & 8000 + 1350 = 9350, we can say that Tank A require 290L/h rate and Tank B require 90L/h rate

Bismuth83 · Answer

1. We're are asked to  calculate the filling rates of tanks A and B while given a few constraints .

2. Let these filling rates (liters/hr) for tanks A and B be equal to a and b, respectively.

3. The amount of water in tank A initially is 5000 and after 15 hours it will be 5000 + 15a. Similarly, the amount of water in tank B initially is 8000 and after 15 hours it will be 8000 + 15b.

4. Lastly, we're given that the amount of water in both tanks will be equal, so,  5000 + 15a = 8000 + 15b \rightarrow 15(a - b) = 3000 \rightarrow a - b = 200 .

5. Since there is no further information, let's look at the combinations that have a difference of 200. Only 1 exists and that's a = 290 and b = 90.

6. Our answer will be:   Tank A fill rate - 290 liters/hr and Tank B fill rate - 90 liters/hr  .

egmat · Answer

Hi there,

Happy to walk you through this one step by step!

Step 1: Identify the two unknowns. 
We need to find the filling rate for Tank A (rA) and the filling rate for Tank B (rB).

Step 2: Set up what each tank holds after  15  hours. 
- Tank A starts with  5,000  liters, so after  15  hours:  5,000  +  15  × rA
- Tank B starts with  8,000  liters, so after  15  hours:  8,000  +  15  × rB

Step 3: Use the key constraint  — after  15  hours, both tanks contain the SAME amount.
So we set them equal:
 5,000  +  15  × rA =  8,000  +  15  × rB

Step 4: Simplify. 
 15  × rA -  15  × rB =  8,000  -  5,000 
 15  × (rA - rB) =  3,000 
rA - rB =  200

Key Insight:  This is the critical equation: Tank A's rate must be exactly  200  liters/hr MORE than Tank B's rate.  This makes sense — Tank A starts  3,000  liters behind, so it needs to fill faster to catch up in  15  hours.

Step 5: Check which pair of choices has a difference of  200 . 
The options are:  30 ,  90 ,  150 ,  220 ,  290 
-   290  -  90  =  200  ✓ 
-   220  -  30  =  190  ✗ 
- No other pair gives exactly  200 .

So rA =  290  liters/hr and rB =  90  liters/hr.

Step 6: Verify the constraints. 
- Tank A after  15  hours:  5,000  +  15  ×  290  =  5,000  +  4,350  =  9,350  liters
- Tank B after  15  hours:  8,000  +  15  ×  90  =  8,000  +  1,350  =  9,350  liters
- Both equal? Yes! Both are  9,350  liters.
- Neither full? Both tanks hold more than  20,000  liters, and  9,350  <  20,000 . Confirmed.

Answer: 290 liters/hr for Tank A (5th option, Column A) and 90 liters/hr for Tank B (2nd option, Column B)

luisdicampo · Answer

Deconstructing the Question

Tank  A  starts with  5,000  liters, and Tank  B  starts with  8,000  liters.

After  15  hours, the two tanks contain the same amount of water.

So Tank  A  must make up the initial gap of  3,000  liters.

The key idea is to use rate difference. If one tank needs to gain  3,000  liters over  15  hours, then its fill rate must exceed the other by  200  liters per hour.

Step-by-step

Initially, Tank  B  has  8000-5000=3000  more liters than Tank  A .

To catch up in  15  hours, Tank  A  must fill faster by:

\frac{3000}{15}=200

So the rates must satisfy:

A-B=200

Now check the answer choices:

30,\ 90,\ 150,\ 220,\ 290

The only pair with difference  200  is:

290-90=200

So:

Tank A fill rate = 290 liters/hr

Tank B fill rate = 90 liters/hr

Quick check after  15  hours:

For Tank  A :

5000+15\cdot 290=9350

For Tank  B :

8000+15\cdot 90=9350

They match, and  9350<20000 , so neither tank is full.

Answer: Tank A = 290 liters/hr, Tank B = 90 liters/hr

Two water storage tanks, Tank A and Tank B, can each hold more than 20

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Tank A fill rate	Tank B fill rate
		30 liters/hr
		90 liters/hr
		150 liters/hr
		220 liters/hr
		290 liters/hr

GMAT Two-part Analysis (TPA) Questions

Two water storage tanks, Tank A and Tank B, can each hold more than 20

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