The puzzler about the husband and wife walking different distances even though they were side-by-side had a booogus answer! The “official answer” is that they were on side-by-side treadmills. The RIGHT answer is that they were walking in circles – the woman on the inside walking a 24’ diameter circle and the man walking a 30’ diameter circle. That puts their centers 3’ apart. The woman can thus walk 4 miles while the man walks 5 miles. Run the math. Try again, guys!!! 
Mike, that was the answer I came up with as well. Your math is correct, and theirs is Bo-oh-oh-oh-gus!
That’s what I had thought as well. The treadmill thing is kinda clever though.
I didn’t enter the contest, so no sour grapes here, but the first time they read it, I thought, that’s one of the easier Puzzlers… obviously: [what MikeVdP said above].
I wonder if they had more walking-in-a-circle answers than treadmill answers.
To be fair, the man did say “5 or 6 miles” but I do like your answer, even though it doesn’t address the possibility of 6 miles.
I’m with you, Mike - I also sent in the walking in circles answer…
I didn’t send in an answer either, because I thought it was so obvious. I didn’t even do the math, until after the wrong answer was told. But I did the math, and for her walking 4 miles, and him 6, it is a 12ft dia circle for her and a 18ft dia one for him for a total of 560.22 laps
Just to nitpick… 
For any distance the two travel, there are an infinite number of solutions for the size of the circle they walk in. The key is that they have to walk the same number of laps to stay side-by-side, and this means that there is simply one unique solution for the diameters of the circles based on the number of laps they travel (or vice-versa).
So, for example, you could say they walked 20 laps. Then if its 4 miles / 6 miles, their circles are 336.14 and 504.20 feet in diameter, respectively. You might be hard pressed to say that is “side-by-side”, but you still get an infinite number of solutions if the difference in diameters is allowed to fluctuate from 2 ft (sort of the minimum possible) to 16 feet (getting to be a bit high to be called “side-by-side”)…
Just to nitpick…
You left out the stipulation that they could hold hands all the way.Was that given as part of the puzzler on the air? It isn’t part of the puzzler on-line…
You are 100% right. It is not in the printed version on the website, but it was in the on-air version. Good catch.
Both answers are possible, but I favor yours.
It ain’t the first Bing of a puzzler. There was one about a traveling salesman, a block heater, and a VW Beetle a while back. What do you expect from a couple of Yobbos that take three halves to get through one show?
BTW, Where are my mid-November episodes? I’m still waiting…
People are NOT horses grinding grain like as in stone horse-mills. The correct answer in our technological world IS a treadmill. Go to the gym and you’ll see many people walking side by side. You can’t walk side by side 6 feet apart, holding hands… unless you are a chimp.
See my post below
…I finally found “The Lost Cartalk Episodes” on podcastdirectory.com after getting BOOOGUS advice from both NPR and iTunes
What I really like was this link: “Text Only listing of NPR: Car Talk Podcast Podcasts”
My daughter and I could touch fingertips when our spines are 6 ft apart. Barely meets the technical spec, and we are not apes. We are 6’ tall, handsome humans.
Besides, the solution, as eraser1998 points out, does not depend on this number. They could instead be walking on radii of 20’ and 25’ (5’ apart), or 16’ and 20’ (4’ apart, 2’ per arm). So you and your significant other, whatever your sizes, could find radii in the ratio 5/4 with any comfortable separation between you.
Both are correct answers. But the treadmill is more of a cop-out IMO.