Question

Difficulty: MediumUnit Conversions

A laboratory dispensing pump releases a liquid solution at a constant rate of 0.75 deciliters per minute0.75\text{ deciliters per minute}. If 1 deciliter=100 milliliters1\text{ deciliter} = 100\text{ milliliters}, what is the pump's dispensing rate, in milliliters per second?

Answer: 1.25 milliliters per second

Answer

The correct answer is 1.25. The pump dispenses 1.25 milliliters per second.
To find the dispensing rate in milliliters per second, we first convert the volume from deciliters to milliliters. Multiplying 0.75 deciliters0.75\text{ deciliters} by 100 milliliters per deciliter100\text{ milliliters per deciliter} gives 75 milliliters per minute75\text{ milliliters per minute}. Next, to convert minutes to seconds, we divide the rate by 6060 (since 1 minute=60 seconds1\text{ minute} = 60\text{ seconds}), which yields 7560=1.25 milliliters per second\frac{75}{60} = 1.25\text{ milliliters per second}.

Step-by-Step Solution

1
Convert the dispensing rate from deciliters per minute to milliliters per minute using the conversion factor 1 deciliter=100 milliliters1\text{ deciliter} = 100\text{ milliliters}.
0.75 deciliters/minute×100 milliliters/deciliter=75 milliliters/minute0.75\text{ deciliters/minute} \times 100\text{ milliliters/deciliter} = 75\text{ milliliters/minute}
This converts the volume unit from deciliters to milliliters.
2
Convert the rate from milliliters per minute to milliliters per second by dividing by 6060, since there are 60 seconds60\text{ seconds} in 1 minute1\text{ minute}.
75 milliliters/minute÷60 seconds/minute=1.25 milliliters/second75\text{ milliliters/minute} \div 60\text{ seconds/minute} = 1.25\text{ milliliters/second}
This converts the time unit from minutes to seconds, yielding the final rate.

Key Concept

Unit Conversions

Alternative Method

Alternatively, you can convert the units in a single dimensional analysis step: 0.75 dL/min×100 mL1 dL×1 min60 s=7560 mL/s=1.25 mL/s0.75 \text{ dL/min} \times \frac{100 \text{ mL}}{1 \text{ dL}} \times \frac{1 \text{ min}}{60 \text{ s}} = \frac{75}{60} \text{ mL/s} = 1.25 \text{ mL/s}.
Estimated Time:1m 30s
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