Three Lamps

The puzzler this week is not automotive in nature. It is non-automotive, as we say here at Car Talk.

Here it is.

There are two windowless rooms. These rooms are on two different ends of a long curved hallway. Both the rooms have doors. So when you're in one room, you can't see into the hallway or the other room around the corner. At all. So basically, you can't see one room when you are in the other.

In one of the rooms, there are three lamps on a table.

And in the other room, down the curved hallway, there are three light switches.

Each of the three switches in one room controls one of the lamps in the other room, all the way down the hall.

And the puzzler is, with the fewest number of visits from room to room, to figure out which lamp goes with which switch. You can turn on one or more of the switches at a time, but then you have to walk all the way to the other room down the hall to figure out which lamp turned on. And then you have to walk back.

And so the question is, what is the minimum number of trips you can take to know which switch controls which lamp?

Answer the Puzzler »

Remember last week's puzzler?

One Word

A few weeks ago, we had a puzzler about a big leaf crusher that we have in our neighborhood. And it was about winterizing it, getting it ready to sit idle for the cold season.

So, I put some stabilizer in the gas tank, started it up got the gas out of the lines, took the spark plugs out, pulled the ripcord out slowly to get it up on the compression stroke so that both valves were closed and no air or rust could get in there. All that stuff.

So back then, my brother had just bought a new lawn mower and decided to do all this stuff with it as the season was ending. He wanted to maintain it so it would stay in good shape. So he does all these things. But when he pulls the ripcord out, the thing won't start.

And he's so mad, because this is a brand new lawn mower, and it should definitely start.

So he goes back inside and calls the shop where he bought it. And tells the guy what's going on. And the guy on the phone gives him a one-word answer.

At first, my brother was annoyed. But after a while, he realized, that the one-word answer was right.

So the puzzler is, what word did my brother hear? What is the one word that explains it all?