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USA TODAY® Related Activities
USA TODAY Related Activities
provides activities related to the concept of the lesson as
well as up-to-date Snapshot data.
A Draining Experience
Materials: calculator, spreadsheet
software (optional)
Work in a group of two or three.
A swimming pool in the shape of a rectangular solid used for
swimming competitions is 50 meters long, 32.5 meters wide, and
2.4 meters deep. Twice a year, the pool is drained and refilled.
There are two drains in the pool. Drain 1 empties the pool at
the rate of 4.25 cubic meters of water per minute. Drain 2 empties
the pool at the rate of 5.75 meters of water per minute. If
both drains are opened at 8 A.M., when will the pool be empty?
To learn a method for solving this problem, complete the steps
below. If you prefer, you can use spreadsheet software.
Procedure for the Activity
Step 1 The first step in solving this problem is to find
the volume of the swimming pool. Recall that the volume of a
rectangular solid can be found by multiplying the length times
the width times the height (depth). What is the volume of the
pool in cubic meters?
Step 2 The second step is to find the amount of water
that passes through each drain in one hour. Recall that there
are 60 minutes per hour. What is the amount of water drained
by Drain 1 in one hour? What is the amount of water drained
by Drain 2 in one hour?
Step 3 Copy or print out the table below. Fill in the
rest of the cells in the table. Use a spreadsheet if you prefer.
| Time |
Amount Drained
by Drain 1 in One Hour
(m3) |
Amount Drained
by Drain 2 in One Hour
(m3) |
Total Amount
Drained by Both Drains
(m3) |
Amount of
Water Left in the Pool
(m3) |
| 8 A.M. |
0 |
0 |
0 |
3900 |
| 9 A.M. |
4.25(60)
= 255 |
5.75(60)
= 345 |
255 + 345
= 600 |
3900 - 600
= 3300 |
| 10 A.M. |
255 |
345 |
600 |
3300 - 600
= |
| 11 A.M. |
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| noon |
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| 1 P.M. |
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| 2 P.M. |
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| 3 P.M. |
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| 4 P.M. |
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| 5 P.M. |
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| 6 P.M. |
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Step 4 When will the pool be empty? Explain how you determined
the time.
Step 5 Describe another strategy that you could use to
find when the pool will be empty.
Wrapping Up the Activity
Solve the problem below and write a one-page summary of the
steps you used to find the solution. Be sure to include any
tables you used in the solution.
Three hoses fill the same
swimming pool as in the activity above. Hose 1 fills at the
rate of 2.25 m3 of water per minute, Hose 2 fills
at the rate of 2.5 m3 of water per minute, and
Hose 3 fills at the rate of 3.25 m3 of water per
minute. If the hoses are turned on at 6 A.M., when will the
pool be filled?
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Test Practice