John trains for ultramarathons.  He starts only able to run 8 hours straight but eventually increases that by 75%.  He also increases his speed of 8 mph by 4 mph.  How far can he run now?
He increases the time he can run by 8*.75=
<gadget id="calculator">8*.75</gadget>
<output>6</output>
6 hours.
So he can now run 8+6=
<gadget id="calculator">8+6</gadget>
<output>14</output>
14 hours.
His speed is now 8+4=
<gadget id="calculator">8+4</gadget>
<output>12</output>
12 mph.
So he can run 14*12=
<gadget id="calculator">14*12</gadget>
<output>168</output>
168 miles.

<result>168</result>