Gas cap puzzler


#1

I get the main point of the puzzler, how the one guy could tell 99% of the time when a car pulled in the wrong way, but how was the other guy right 50% of the time? Their contest isn’t to guess which side the cap is on (which probably isn’t 50/50 anyway), it’s to guess when a driver pulls in the wrong side.



Most people are driving their own car, and know which side their gas cap is on. The only people who get it wrong are either driving a new car, a borrowed car, or a rental, plus a few forgetful or distracted drivers.



Let’s say 1 out of 20 people pull in the wrong side. If the one guy is just guessing randomly, even if he knows that on average 1 out of 20 people pull in wrong, he’s going to guess the wrong car 19 out of 20 times.



The only way he’s going to be right 1/2 the time is if NO drivers know where their gas cap is. The drivers will guess right 1/2 the time. By randomly guessing 1/2 the cars, he’s going to be right, on average, 1/2 the time.



Even though it doesn’t really affect the puzzler answer, it bothers me how they think the other guy gets it right 1/2 the time by guessing.


#2

Change the odds. Most cars have a icon of a fuel pump at the gas gauge. If you look at the Icon, you will noticed that it has the hose on the same side the filler is on. Also if you look at the back of the car, you will notice that most if not all cars have the filler on the side away from the exhaust.


#3

Change what odds, to what? How does that apply to my question about how the guesser got it right 1/2 the time? I know the filler is on the side away from the exhaust, that’s the puzzler answer, but has nothing to do with what I asked. Apparently the guesser does not know this fact, or he’d have gotten it right 99% of the time like his buddy did.


#4

I don’t understand how or why the words “guessing randomly” are use in conjunction with eachother If you use any information what so ever in making your choice are you still guessing? I say no, you are making a choice based upon the information you know, not a guess, how does “randomly” fit in here? Lets just say I don’t get that paragraph at all.

Perhaps it can be explained if we define “non-random” guessing. Whould non-random guessing be when you use a system like every other car.


#5

From the puzzler question: “Tim was correct about 50 percent of the time, because he was just guessing.”

There’s only one piece of information you can use that helps at all when viewing only the back of the car. That’s the location of the tail pipe. That’s how Jethro got it right 99% of the time. Tim doesn’t know about that, so he isn’t getting it right 99% of the time.

How did Tim get it right 50% of the time without any useful information? Statistically, the only way that’s possible is if none of the drivers knew which side their gas caps were on, such that half of them would pull up on the wrong side. But most drivers do know, so Tim is going to guess a lot of times that they pulled up on the wrong side when they didn’t. Every once in awhile they will pull up on the wrong side and Tim won’t predict it. And once in a great while, they will pull up on the wrong side and Tim will have guessed it and have been right. Nowhere close to 50%.

If Tim’s not guessing randomly, what information is he using to get it right 50% of the time? Jethro has useful information. Tim has none. Thus, he is randomly guessing.

Please actually think about this before posting. It’s not a left side or right side, 50/50 question.


#6

What leads you to believe I did not actually think about what YOU posted before I posted? Telling people when they can and can’t post, well get your own website and have at it, otherwise, just deal with it.


#7

Well then enlighten me as to how Tim guessed right 50% of the time by guessing. If it was non-random guessing, what information is there that gets him 50% and not 99% like the other guy?


#8

Like I asked initaly what is “non-random guessing”?


#9

If you have some information that helps, that would be non-random guessing. What information would that be in this case, other than looking at the tailpipe, which would get you 99%, not 50%?


#10

You kids get off my lawn!!!

Full disclosure: I did not solve this puzzler.


#11

You’re kind of right. He could have done much better by always betting that they pulled up with the gas cap on the proper side. It’s simply unrealistic to think he could achieve 50 % by guessing.


#12

And I’d prove 'em both wrong.
I CHOOSE to pull up with the filler away from the pump if it’s the soonest available pump, it doesn’t bother me in the slightest.

So how would these guessers know that…
I didn’t get it WRONG.
I got it exactly as I chose.

AND how many other drivers do the same ?

? WRONG ? side…maybe not.

My 79 pickup has caps on both sides.


#13

WELL, (hands on hips) that certainly does change the chances but you must be in the minority. I was wondering what percentage of cars are right side and what are left, and what about my old nova with the filler behind the license plate? Caps on both sides? is your tailpipe in the middle?


#14

An interesting study could be done at the Costco where ALL cars enter from just one side of the lot. Therefore, four lanes are on the pump’s left and four on the right. I’ve never counted nor asked people ( & only began recently to notice due to these discussions about filler sides ) but you see a great number pulling the hose over to the side away from the pump. It seems the common practice is to try to guess which LANE will be quicker and just go with that. I do see a few incoming cars choose a longer line to fill on the inside.

At the Costco, how many people have chosen to fill on the outside and how many ‘got it wrong’ ?

The 79 chevy pickup has twin tanks, right and left. The ones that stirred up such a stink and a recall years ago being mounted outside the frame rails. No matter where I go I have to stretch the hose over and it seems I get many a smirky glare that I’ve stupidly pulled to the ‘wrong’ side of the pump. I always fill the outside first so ‘those’ people can see me fill the inside too .

It’s the end of the day in my shop, many stalls are empty. It is 10 driver side to 3 passenger side fillers.


#15

What I’d like to know is WHY the manufacturers put the gas cap on the opposite side from the tail pipe. Is there some obvious design or safety consideration that eludes me? (And in that case what about cars with twin tailpipes?)


#16

I’m kinda curious about that too. I had an 86 Toyota Tercel 4wd wagon. The exhaust was on the drivers side and the gas cap on the passengers side. The FWD version of the same vehicle has the gas cap on the drivers side and the exhaust on the passengers side. Go figure.

What was really odd about that was the amount of bending it took to get the exhaust from the manifold on the passengers side of the engine (engine is fore and aft in both vehicles) to the drivers side on the rear, over the driveshaft. The FWD didn’t even have a driveshaft to contend with, but it went straight back.


#17

My guess would be that this could reduce the chance of overfilling the tank and having the gasoline spill down onto a hot exhaust pipe or muffler.