The tripodasaurus has three legs. In a flock of tripodasauruses, there is a total of 20 heads and legs. How many tripodasauruses are in the flock?
Each animal has 1+3=
<gadget id="calculator">1+3</gadget>
<output>4</output>
4 total heads and legs.
Then there are 20/4=
<gadget id="calculator">20/4</gadget>
<output>5</output>
5 in the flock.

<result>5</result>