If it takes 20 minutes to paint a house, how many houses can you paint in 3 hours?
There are 3 hours * 60 minutes/hour =
<gadget id="calculator">3*60</gadget>
<output>180</output>
180 minutes in 3 hours.
You can paint 180 minutes / 20 houses/minute = 9 houses in 3 hours.

<result>9</result>