Puzzler of the week

[Scott MacLean]

This week's puzzler:

It was a dark and stormy night at a secret airfield somewhere in England during WW II. The Royal Air Force had summoned one of England's most noted mathematicians to help them solve a problem. German anti-aircraft fire based on the ground was inflicting heavy losses on the Brits. Their planes were being shot down right and left. The RAF had to do something to diminish their losses.

Clearly, they could put armor plating on the bottoms of the fuselages and the wings, but there were several problems with that idea. Their range and their ability to carry bombs would be considerably reduced because of the additional weight.

A nameless mathematician crawled underneath the planes and looked at where the bullet holes were on the underside. They were all over the place as you might expect -- in the wings and the fuselage, and seemingly distributed randomly on the undersides. He studied hundreds of planes, took pictures, drew a number of sketches -- and then he made his recommendation.

The question is, what armor plating, if any, did he recommend putting on these planes -- and why?

Last week's puzzler:

It was a dark and stormy night. You're on Isle Nubar off Costa Rica. You're in your Nissan Pathfinder and you're being pursued by Tyrannosaurus Rex.

Your only hope is to get off the island. Otherwise, you're going to be passing through the digestive system of said Rex. You have to make it to the dock because that's where your little boat is. If you don't make it to the dock -- you're done for!

The pterodactyls are circling overhead. You're driving along, and you come to a fork in the road. One road takes you to certain death because you don't know where that goes. The other one takes you to the dock where your little boat awaits.

Sitting at the fork are two guys. Now, on this island there are either liars or truth tellers. You know one road leads to death; the other to the dock. You can ask one question of either one of the two guys. One of these guys is a liar and one of them is a truth teller.

You have no way of identifying them. Is there one question you can ask of either of these guys that will unquestionably get you on the right road to the dock?

Last week's puzzler answer:

Here's the question I would ask. I would look at one of the guys and say, "If I were to ask the other guy which road takes me to the dock, what would he say?"

If you ask the truth teller, it's pretty simple, right? The truth teller will say the liar is going to tell you to take this road, which is-which is obviously the wrong road because that guy's a liar.

Now you ask the liar the same question, and he has to point to the same road-because otherwise he'd be telling the truth.