I'm also not familiar with a foot. Unless you mean [he gestures in the direction of his ankle] feet.

But forty-five minutes at a walking pace -- hmm.

I've never seen a car but I've heard of them.... [He trails off, doing mental math. Thirty-five hundred divided by five days divided by twenty-four hours to the day if you travel without resting, for a minimum necessary speed--]

Are they really that much faster than a galloping horse? [His eyebrows are soaring. Taking any of the roads he knows at a horse's gallop is already a serious risk to life and limb. And it would require weeks for anyone to travel from one end of Shangri-la to the other....]