Kara notices that every 6 drops from the loose cap of her sports water bottle together make 5 ml of water. The cap drips at 4 drops per second. How many seconds will it take for 10 ml of water to leak out?
Need a hint?
First convert 10 ml into a number of drops using the information about 6 drops and 5 ml.
Worked answer
- 10 ml is 2 times 5 ml, so it takes 6 × 2 = 12 drops.
- 12 drops ÷ 4 drops per second = 3 seconds.
Answer: 3 seconds
The mistake this question tests
Habit
Minutes and hours in rate
A pupil may work out 10 ÷ 4 = 2.5 seconds, treating millilitres as drops. The millilitres must first be changed into drops.
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