I know that the answer is in there but it seems like he is trying to make it confusing... since it appears that he already did the math and didn't post the numbers with the same units. But thank you.
There's a distinct difference between time at indicated airspeed (which is what calculations based on fuel consumption per unit time are based around) and the ground distance you'd cover. Ground-dwellers - that is, most readers - are comfortable with miles per gallon (or, say, litres per hundred kilometres), but it's a useless number as an aircraft spec.
