# Answer my mind teaser! **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [August 4, 2005, 6:03pm UTC](https://boards.straightdope.com/t/answer-my-mind-teaser/315595 "2005-08-04T18:03:13Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Philster](https://avatars.discourse-cdn.com/v4/letter/p/13edae/32.png) [@Philster](https://boards.straightdope.com/u/Philster)\ **Post date:** [August 4, 2005, 6:03pm UTC](https://boards.straightdope.com/t/answer-my-mind-teaser/315595/1 "2005-08-04T18:03:13Z")
Quickly answer: I have a hybrid gas/electric car. It gets 50 mpg using electric and gas. I have a gas car, it gets 50 mpg using just gas. Which one burns more gas? Answer! Now, I tried this around the office, and 4/5 people were wrong, and it started arguments left and right. People are still trying to convince people who don’t get it and some are trying to argue with me! ---
**Author:** ![Hoodoo\_Ulove](https://avatars.discourse-cdn.com/v4/letter/h/58956e/32.png) [@Hoodoo\_Ulove](https://boards.straightdope.com/u/Hoodoo_Ulove)\ **Post date:** [August 4, 2005, 6:08pm UTC](https://boards.straightdope.com/t/answer-my-mind-teaser/315595/2 "2005-08-04T18:08:32Z")
Whichever one you drive more miles. ---
**Author:** ![lieu](https://avatars.discourse-cdn.com/v4/letter/l/c2a13f/32.png) [@lieu](https://boards.straightdope.com/u/lieu)\ **Post date:** [August 4, 2005, 6:14pm UTC](https://boards.straightdope.com/t/answer-my-mind-teaser/315595/3 "2005-08-04T18:14:26Z")
The hybrid, because it’s only with electric assistance that it get the same as your gas only car. ---
**Author:** ![Daithi\_Lacha](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/daithi_lacha/32/5430_2.png) [@Daithi\_Lacha](https://boards.straightdope.com/u/Daithi_Lacha)\ **Post date:** [August 4, 2005, 6:15pm UTC](https://boards.straightdope.com/t/answer-my-mind-teaser/315595/4 "2005-08-04T18:15:12Z")
They both get the same mileage, since you’re giving the measurements in gallons. What do I win? ---
**Author:** ![Bricker](https://avatars.discourse-cdn.com/v4/letter/b/977dab/32.png) [@Bricker](https://boards.straightdope.com/u/Bricker)\ **Post date:** [August 4, 2005, 6:22pm UTC](https://boards.straightdope.com/t/answer-my-mind-teaser/315595/5 "2005-08-04T18:22:59Z")
Whichever car is driven more miles will use more gas. If each car is driven an equal distance, they will use an equal mount of gas. ---
**Author:** ![Emerald\_Hawk](https://avatars.discourse-cdn.com/v4/letter/e/e495f1/32.png) [@Emerald\_Hawk](https://boards.straightdope.com/u/Emerald_Hawk)\ **Post date:** [August 4, 2005, 6:34pm UTC](https://boards.straightdope.com/t/answer-my-mind-teaser/315595/6 "2005-08-04T18:34:28Z")
It’s a trick question. You are secretly a highly skilled auto mechanic/electrician and modified your hybrid car to allow it to receive power from to a diesel generator you keep out back. This charges the batteries, which you then run down while driving it around town (you have modified the car’s software to allow it to do this). When you say 50 mpg, you are referring only to the regular unleaded you put in it at the pump, not the diesel used in the generator. Therefore, the hybrid car burns more total fuel if driven the same distance, counting this extra diesel! 😉 All questions are trick questions, and I have an overactive imagination. ---
**Author:** ![Philster](https://avatars.discourse-cdn.com/v4/letter/p/13edae/32.png) [@Philster](https://boards.straightdope.com/u/Philster)\ **Post date:** [August 4, 2005, 8:37pm UTC](https://boards.straightdope.com/t/answer-my-mind-teaser/315595/7 "2005-08-04T20:37:27Z")
Let me rephrase, since this is not a wording trick…it’s just about a hybrid and gas car getting the same mpg: _Which gets better mileage?_ (They get the same mileage – they burn the same amount of gas to go the same distance, but the answer varies widely, and arguments ensue. There is no ‘trick’ in the wording. People are convinced that a hybrid getting 50mpg is using less gas than a gas car getting 50 mpg!) ---
**Author:** ![treis](https://avatars.discourse-cdn.com/v4/letter/t/bc79bd/32.png) [@treis](https://boards.straightdope.com/u/treis)\ **Post date:** [August 4, 2005, 8:49pm UTC](https://boards.straightdope.com/t/answer-my-mind-teaser/315595/8 "2005-08-04T20:49:21Z")
Philster, I am afraid you may be working with morons. ---
**Author:** ![Ponder\_Stibbons](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ponder_stibbons/32/343_2.png) [@Ponder\_Stibbons](https://boards.straightdope.com/u/Ponder_Stibbons)\ **Post date:** [August 4, 2005, 9:01pm UTC](https://boards.straightdope.com/t/answer-my-mind-teaser/315595/9 "2005-08-04T21:01:48Z")
Crazy, isn’t it? Yea, **Philster** , it’s strange. I mean, if they get the same mileage, then they get the same mileage. Mileage == MPG == “Amount of Gas Burned”. The better question, in such a situation, is _how_ does the non-hybrid mentioned get such great mileage? ---
**Author:** ![Inigo\_Montoya](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/inigo_montoya/32/124_2.png) [@Inigo\_Montoya](https://boards.straightdope.com/u/Inigo_Montoya)\ **Post date:** [August 4, 2005, 9:07pm UTC](https://boards.straightdope.com/t/answer-my-mind-teaser/315595/10 "2005-08-04T21:07:27Z")
Heh…Which weighs more, a pound of feathers or a pound of brains? Which is hotter, red hot iron or red hot lead? ---
**Author:** ![Ethilrist](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ethilrist/32/4604_2.png) [@Ethilrist](https://boards.straightdope.com/u/Ethilrist)\ **Post date:** [August 4, 2005, 9:12pm UTC](https://boards.straightdope.com/t/answer-my-mind-teaser/315595/11 "2005-08-04T21:12:41Z")
More importantly, although the vehicles are burning the same amount of gas per mile, the hybrid car is, over its lifespan, generating _more_ dead batteries… so much for being better for the environment… ---
**Author:** ![robardin](https://avatars.discourse-cdn.com/v4/letter/r/43a26b/32.png) [@robardin](https://boards.straightdope.com/u/robardin)\ **Post date:** [August 4, 2005, 9:26pm UTC](https://boards.straightdope.com/t/answer-my-mind-teaser/315595/12 "2005-08-04T21:26:35Z")
> [@Philster](#): > > Let me rephrase, since this is not a wording trick…it’s just about a hybrid and gas car getting the same mpg: > > _Which gets better mileage?_ > > (They get the same mileage – they burn the same amount of gas to go the same distance, but the answer varies widely, and arguments ensue. There is no ‘trick’ in the wording. People are convinced that a hybrid getting 50mpg is using less gas than a gas car getting 50 mpg!) That’s very depressing. It reminds me of an interview candidate we had in here 2 years ago who is now famous for getting a simple probability question wrong. Now it’s not too uncommon for people to get it wrong at first, but then we talk them through to the right answer, and for an entry level candidate, the question is as much to see how the person will be to work with and teach as to see if they get the analysis right. Here’s how it went: **Q** uestioner: Suppose there is an anti-aircraft gun that has a 1-in-3 chance (33%) of hitting its target. You have two of these guns positioned at a location, and an enemy plane flies over head. Both guns fire. What is the probability that the plane is hit? **I** nterviewee (with no hesitation): 66%. **Q** : OK, and what if you had three such guns fire? **I** (again with no hesitation): 100%. **Q** : Really? What if you had _four_ guns? At this point a candidate who has made the naive mistake of summing the probabilities catches on that something is wrong with their thinking. Not this guy. **I** (no hesitation): 133%. **Q** (after blinking for a few seconds): What would that mean? **I** (pauses for the first time, then says): That 3 guns are better than 2? **Q** : But you just said that 2 guns have a 100% chance of hitting the plane, so it’s definitely hit. How much better can it get? **I** : Maybe it takes more than one hit to bring the plane down. So now the Questioner proceeds to show the interviewee the tree graph of probabilities, and how the first gun has a 33% chance of hitting the plane, and the second gun has an additional 33%\*66% chance of hitting when the first gun misses. The Interviewee looks on and grunts occasionally. **Q** : So now do you see how probability works? **I** (scowls and waves hand irritably): Well, **if that’s how you define probability.** :eek: This was someone coming in with a degree in Electrical Engineering, which makes it even sadder/funnier. ---
**Author:** ![robardin](https://avatars.discourse-cdn.com/v4/letter/r/43a26b/32.png) [@robardin](https://boards.straightdope.com/u/robardin)\ **Post date:** [August 4, 2005, 9:36pm UTC](https://boards.straightdope.com/t/answer-my-mind-teaser/315595/13 "2005-08-04T21:36:32Z")
D’oh! People sometimes ask this question with a 50% chance rather than 33% chance, so of course the ending of my little transcript should have been: > [@robardin](#): > > **I** (no hesitation): 133%. > **Q** (after blinking for a few seconds): What would that mean? > **I** (pauses for the first time, then says): That **4** guns are better than **3**? > **Q** : But you just said that **3** guns have a 100% chance of hitting the plane, so it’s definitely hit. How much better can it get? > **I** : Maybe it takes more than one hit to bring the plane down. What’s that rule again about how postings meant to ridicule/criticize others often contain an example of the same fault therein? ---
**Author:** ![Cornelius\_Tuggerson](https://avatars.discourse-cdn.com/v4/letter/c/13edae/32.png) [@Cornelius\_Tuggerson](https://boards.straightdope.com/u/Cornelius_Tuggerson)\ **Post date:** [August 4, 2005, 10:37pm UTC](https://boards.straightdope.com/t/answer-my-mind-teaser/315595/14 "2005-08-04T22:37:07Z")
> [@Inigo Montoya](#): > > Which is hotter, red hot iron or red hot lead? I don’t get it. Lead boils at a higher temperature then iron, so it wouldn’t be unreasonable to assume that you have to heat it up more then iron to make it glow red. Whats the catch? ---
**Author:** ![Inigo\_Montoya](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/inigo_montoya/32/124_2.png) [@Inigo\_Montoya](https://boards.straightdope.com/u/Inigo_Montoya)\ **Post date:** [August 4, 2005, 10:58pm UTC](https://boards.straightdope.com/t/answer-my-mind-teaser/315595/15 "2005-08-04T22:58:45Z")
bjects glow depending on the [TEMPERATURE](http://www.squ1.com/index.php?http://www.squ1.com/concepts/color-temperature.html). It may take more HEAT (ENERGY) to get an object to “red hot” but if two objects are glowing the same, neither is hotter. Not all that obvious I guess. Sorry. I’ll go now. ---
**Author:** ![Baldwin](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/baldwin/32/7264_2.png) [@Baldwin](https://boards.straightdope.com/u/Baldwin)\ **Post date:** [August 4, 2005, 11:00pm UTC](https://boards.straightdope.com/t/answer-my-mind-teaser/315595/16 "2005-08-04T23:00:26Z")
> [@](#): > > More importantly, although the vehicles are burning the same amount of gas per mile, the hybrid car is, over its lifespan, generating more dead batteries… so much for being better for the environment… That’s one of several factors. The hybrid car is probably much lower in emissions than the other car. Also, we’re not told their relative weights. If the hybrid car gets 50 mpg while carrying four adults and luggage at highway speed, and the gas car can only achieve the same mileage empty, with an adolescent Romanian female gymnast at the wheel, then the hybrid is definitely more efficient transportation. ---
**Author:** ![BobLibDem](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/boblibdem/32/3149_2.png) [@BobLibDem](https://boards.straightdope.com/u/BobLibDem)\ **Post date:** [August 4, 2005, 11:03pm UTC](https://boards.straightdope.com/t/answer-my-mind-teaser/315595/17 "2005-08-04T23:03:30Z")
The hybrid. The electricity to recharge the batteries had to come from somewhere. ---
**Author:** ![wolf\_meister](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wolf_meister/32/15202_2.png) [@wolf\_meister](https://boards.straightdope.com/u/wolf_meister)\ **Post date:** [August 5, 2005, 12:16am UTC](https://boards.straightdope.com/t/answer-my-mind-teaser/315595/18 "2005-08-05T00:16:35Z")
or as they say in Europe, it gets 4.7 liters per 100 kilometers. [http://www.1728.com/convmlge.htm](http://www.1728.com/convmlge.htm) ---
**Author:** ![Spatial\_Rift\_47](https://avatars.discourse-cdn.com/v4/letter/s/a8b319/32.png) [@Spatial\_Rift\_47](https://boards.straightdope.com/u/Spatial_Rift_47)\ **Post date:** [August 5, 2005, 1:05am UTC](https://boards.straightdope.com/t/answer-my-mind-teaser/315595/19 "2005-08-05T01:05:36Z")
> [@BobLibDem](#): > > The hybrid. The electricity to recharge the batteries had to come from somewhere. I’m reasonably certain that internal combustion isn’t a widespread method of generating electrical power, therefore the hybrid didn’t use any additional gasoline to charge its battery. ooh look, a nit! :: pick, pick, pick :: ---
**Author:** ![treis](https://avatars.discourse-cdn.com/v4/letter/t/bc79bd/32.png) [@treis](https://boards.straightdope.com/u/treis)\ **Post date:** [August 5, 2005, 1:16am UTC](https://boards.straightdope.com/t/answer-my-mind-teaser/315595/20 "2005-08-05T01:16:34Z")
> [@Inigo Montoya](#): > > bjects glow depending on the [TEMPERATURE](http://www.squ1.com/index.php?http://www.squ1.com/concepts/color-temperature.html). It may take more HEAT (ENERGY) to get an object to “red hot” but if two objects are glowing the same, neither is hotter. > > Not all that obvious I guess. Sorry. I’ll go now. Really? Its been a while since Chemistry but I thought different energy levels give off differen’t colors of light. [Next page](https://boards.straightdope.com/t/answer-my-mind-teaser/315595.md?page=2)