John decides to do several activities while out on vacation.  He spends 6 hours boating and half that time swimming.  He also watched 3 different shows which were 2 hours each.  This was 30% of the time he spent.  He spent 40% of his time sightseeing.  How much time did he spend sightseeing?
He spent 6/2=
<gadget id="calculator">6/2</gadget>
<output>3</output>
3 hours swimming.
He spent 3*2=
<gadget id="calculator">3*2</gadget>
<output>6</output>
6 hours watching shows.
So he spent 6+3+6=
<gadget id="calculator">6+3+6</gadget>
<output>15</output>
15 hours on these activities.
That means he spent 15/.3=
<gadget id="calculator">15/.3</gadget>
<output>50</output>
50 hours on activities.
So he spent 50*.4=
<gadget id="calculator">50*.4</gadget>
<output>20</output>
20 hours sightseeing.

<result>20</result>