Chris has a two-speed lawn mower. He can mow his entire lawn in "turtle" mode in 1 hour, or 40 minutes in "rabbit" mode. Today, he experimented by mowing half in turtle mode and half in rabbit mode. How many minutes did it take him to mow the lawn?
He spends 60/2=
<gadget id="calculator">60/2</gadget>
<output>30</output>
30 minutes in turtle mode.
He spends 40/2=
<gadget id="calculator">40/2</gadget>
<output>20</output>
20 minutes in rabbit mode.
He took 30+20=
<gadget id="calculator">30+20</gadget>
<output>50</output>
50 minutes to mow the lawn.

<result>50</result>