John decides to get the vaccine for COVID.  He has to wait 20 minutes for the first dose.  The second dose has a wait time half as long.  How long was the total wait time?
The second dose had a wait time of 20/2=
<gadget id="calculator">20/2</gadget>
<output>10</output>
10 minutes.
So the total wait time is 20+10=
<gadget id="calculator">20+10</gadget>
<output>30</output>
30 minutes.

<result>30</result>