Leaks and Fills Practice Test Worksheets
Build confidence with printable volume, capacity, and flow-rate maths worksheets. These focused practice tests help students master litres and millilitres conversions, rate and time calculations, and multi-step word problems.
For students who understand multiplication and division, but need focused practice choosing the right rate formula and converting capacity units.
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What Do Leaks and Fills Questions Look Like?
Leaks and fills questions describe containers filling up, draining, or leaking at a constant rate. You are given flow rates, container capacities, or elapsed times and asked to calculate the volume added, the time required, or the remaining capacity. Here is a worked example.
A tap uses water at a constant rate of 13 litres per minute. How many litres are used in 10 minutes?
13 litres/min × 10 min
= 130 litres
Rate × time = total volume.
Worked Method
Rate: 13 litres per minute. Time: 10 minutes.
Volume = Rate × Time: 13 × 10 = 130 litres.
Tip: The units already match, so no conversion is needed.
Rules to Help You Solve Leaks and Fills Questions
These questions assume a constant flow rate. Using the relationships from the example above, identify the volume being added or removed, match the units, then use the relationship between volume, rate, and time.
💧 Rule 1: Volume = Rate × Time
Multiply the amount flowing each minute by the number of minutes to find the total volume added or lost.
Example: 100 ml per minute for 25 minutes = 2,500 ml.
⏱️ Rule 2: Time = Volume ÷ Rate
Divide the volume to add or remove by the flow rate. Use the full capacity only when filling an empty container completely or draining a full one; otherwise, use the volume still needed or the water actually present.
Example: 1,500 ml ÷ 100 ml per minute = 15 minutes.
🚰 Rule 3: Rate = Volume ÷ Time
Divide total volume by total time when the flow rate is unknown.
Example: 4,000 ml ÷ 5 minutes = 800 ml per minute.
🔄 Rule 4: Match Units Before Calculating
Match both volume and time units to the rate before using a formula. One litre equals 1,000 millilitres, and one minute equals 60 seconds. For a rate per minute, use time in minutes.
Volume example: 7.5 litres = 7,500 ml.
Time example: 360 ml ÷ 240 ml per minute = 1.5 minutes. Multiply the fractional part by 60: 0.5 × 60 = 30 seconds, so the answer is 1 minute 30 seconds.
Two More Worked Examples
Here are two additional problems showing how to convert between litres and millilitres and how to calculate the remaining volume needed to fill a container.
A pipe fills an empty 7.5-litre pitcher at a constant rate of 75 ml per minute. How many minutes will it take to fill?
Empty pitcher: 7.5 litres capacity
7.5 litres = 7,500 ml
7,500 ÷ 75 = 100 minutes
Convert, then divide by the flow rate.
Worked Method
Convert first: 7.5 litres = 7,500 ml.
Time = Volume ÷ Rate: 7,500 ÷ 75 = 100 minutes.
Tip: Keep the units consistent: using millilitres with millilitres per minute gives a time in minutes.
An empty 8-litre bucket fills at a constant rate of 250 ml per minute. After 8 minutes, how much more water is needed to fill it? Give your answer in litres.
8 litres capacity · 2 litres added
250 ml/min × 8 min = 2,000 ml
8,000 ml − 2,000 ml = 6,000 ml
6 litres still needed
Worked Method
Convert capacity: 8 litres = 8,000 ml.
Find water already added: 250 × 8 = 2,000 ml.
Subtract from capacity: 8,000 - 2,000 = 6,000 ml = 6 litres.
Tip: The question asks for the water still needed, not the water already added.
