There are 5 houses on a street, and each of the first four houses has 3 gnomes in the garden. If there are a total of 20 gnomes on the street, how many gnomes does the fifth house have?
In the first four houses, there are a total of 4 houses * 3 gnomes = 
<gadget id="calculator">4*3</gadget>
<output>12</output>
12 gnomes.
Therefore, the fifth house had 20 total gnomes - 12 gnomes = 
<gadget id="calculator">20-12</gadget>
<output>8</output>
8 gnomes.

<result>8</result>