Puzzle at a 711 store
Posted on November 3rd, 2009 by James Higham
A customer at a 7-11 store selected four items to buy, and was told that the cost was $7.11. He was curious that the cost was the same as the store name, so he enquired as to how the figure was derived. The clerk said that he had simply multiplied the prices of the four individual items. The customer protested that the four prices should have been ADDED, not MULTIPLIED. The clerk said that that was OK with him, but, the result was still the same: exactly $7.11. What were the four prices?
Filed under: Diversions
A quick question .. .. .. is the multiplication EXACTLY $7.11 or do normal rounding rules apply?
I think setting up a little math equation can solve that, but is that cheating? Couldn’t figure it out for myself without the maths, but instead of giving the answer so soon, how about a hint? I’d offer:
3.a / 1.b / 1.c / 1.d
So find a, b, c and d
Capn – it’s exact.
Andrew – no problem at all – that’s how I do it.
Thanks! Back to the drawing board for me then.
Ah well, then I claim victory, but won’t spoil the captain’s fun.
But where are your four actual prices, Andrew?
They’re sitting in front of me. But I am not revealing them because that would spoil the fun, but they are exact and give the exact answer, and only need two decimal places so could be real prices in dollars and cents. I’ve got em
The clock is ticking captain…
3.16 / 1.25 / 1.?? / 1.??….
time’s up…then also 1.5 and 1,2.
So 3.16, 1.25, 1.5 and 1.2
I asked about the maths issue James because I once did some MENSA puzzles and was told by the MENSA guru that my method was “cheating” rather than “intelligence”. Oh well… what works works
Official answer: $1.20, $1.25, $1.50, and $3.16
Mensa material, Andrew!
I gave a lecture to a MENSA residential meeting many years ago, at Queens College in Cambridge University. This was when that exchange I referred to in my previous comment took place. Mostly very nice but predominantly rather strange people; although the sample size was only about 50. But since I was apparently “cheating” I decided not to join
Andrew,
I assume you used trial and error to get it, narrowing it down each iteration.
If so its the same as I do with allmy puzzles. I’m no maths genius.
So no magic equation = cheating.
Nope. Didn’t use trial and error – that’s messy. I used an algorithm that goes straight to the solutions. My secret
Andrew, the IQ test for MENSA is that you fail the moment you join them ;>
We had a MENSA guy in out year in uni for a short while, he had a MENSA credit card, a MENSA lighter and a chunky MENSA bling ring… very cool.
I have to say, his academic efforts we a bit grim tho and as far as I can tell, MENSA is simply a social club that is making £££’s from people’s displaced vanity.
Just for fun, here is a puzzle that occurred to me one day as I was sitting idly in the park: What is the true meaning of 42? — and yes, there is a proper answer, it’s mathematical AND linguistic at the same time, then chose number is no accident, Mr. Adam had a wicked kind of humour (and if he didn’t, then this is a spiffy coincidence).
Bleah, my keyboard is dying and I can’t spell. My chickencoop for and edit function… :>
Dunno about 42 Fat Hen, though I know plenty theories, from cosmological constants and stuff about maths to the base 13 to the fact that in Wonderland Alice went “For Tea Too” at the Mad Hatter’s party
and the Adams’ claim that it means nothing at all, which was actually the point. So what’s your one? I give up. By the way, I was never trying to join MENSA, I was just annoying them by criticising their puzzles when we had a long boozy meal after my lecture – but “a MENSA bling ring”? Wear one of them and that would PROVE your IQ score has no relationship to intelligence 
Andrew, trust me, there is a very pleasing, perfect answer, and it made my day when I had the satori about it. So, I’m not going deprive you of the fun! Don’t give up (yet!) :>
Because this is such an entrenched problem (as in too many people have thought too long about and believe there is no solution as such) here are 3 hints that will help you solve:
Hint 1: Use what you know (and I know you know!)
Hint 2: How good is your cockney?
Hint 3: What was the reason for the question again?
———
Jokes aside, the MENSA guy was actually quite a sad sausage, he ended up struggling hard on his own because he laid it on so thickly with this alpha genius MENSA BS, and then tried to hide that he was falling behind, he didn’t even turn up for the end of the second year. He was a mature student and you can imagine what that fail must have cost him financially… ouch. We tried to get him to join our study group, but no amount of coaxing could help him safely off that stupid high horse that MENSA managed to flog him.
He was not hopeless at all either, but one of those self-taught guys who have many reasons to be proud and who got to where they are because they are a bit full of themselves (eh, someone has to believe in them, if only they themselves!) — but who do not have enough basic, solid education to make more of their obvious talents.
In his defense, it’s actually quite hard to look at an offical looking org like MENSA critically and realise that they are not mainstream but a money-making con that preys on insecure folk with dreams, especially when you feel flattered by their attentions(hey, who doesn’t like to be a real, certified genius(tm)?). Normally I think that people have to look after themselves, but in MENSA’s case… yeah, it would be nice to see the vanity scam taken apart properly, starting with the lame puzzles they peddle. :>
Well I’ll think about it Fat Hen, and will get back if inspiration strikes. My Cockney? Not one of my strong points Daalin’
(Although that emoticon is a Smiley Boat, I believe, as in Boat Race 
I’m enjoying this.
Ahha! I’ve cracked it Skinny Chicken! You are not what you seem. Not a Fat Hen at all. You’re just pretending that you have an answer because you think my @smart ass attitude” to the earlier puzzles means I need to be taken down a peg or forty two.
However… to a Cockney “Deep Thought” would be pronounced “Deep Fought” wouldn’t he? And if he was a mate “daan the pub” he would be just called “Foughty”, pronounced a bit like “Forty” So who are we gonna get to find out the meanin of life the universe and everythin Daalin?
“Let’s get Forty to”………….
Nah… maybe not… I’m gonna just get some mice to figure it out instead….
Hey now, I’m not leading you a wild hen chase (I’m far too fat to run fast… heh)
This is a bonafide puzzle, and just to be fair (as some people would be cheeky like that) I will email James the solution and he can arbitrate.
=)
Well Fatty, Bald Eagle here: How about if instead of the answer I just tell you the question? After all, that was supposed to be harder wasn’t it? Haven’t had time to apply my neuronal machine to this issue today, but I think it is going to need a better one than mine (Can there be such a thing??!!). Hopefully someone else will step in and erase my failure. But I’m thinking… slowly…
I suspect some sort of love affair going on here.
Not sure about the feasibility of that James – a bald eagle and a fat hen?
James should have the solution by now, at least I emailed him with it. Shout if you haven’t got it James.
So take your time Andrew, I’m in no hurry and I enjoy torturing people, especially when I know they enjoy a tough puzzle =)
=*=*=*=*=*=*=*=
Love affair between a hen and an eagle? Oh my, James is going to start writing Mills & Boons novels next with this imagination!
My vast team of researchers tell me Cockney rhyming slang for 42 is Winnie the Poo. Oh so that helps me a lot… Nearly there actually… check back with me in a few million years… You see this is the problem, the Cockney link you meant is probably not the one I found. It’s a badly designed puzzle. Your fault. Not mine
Andrew, the prize for not solving is a free MENSA membership.
Let me know when you want to claim it =)
Free MENSA membership? Surely I’m not thick enough to deserve that! Element 42 is Molybdenum, by the way M for meaning, O for of, L for life, Y for Youniverse, B for Bugger it this is not working…. And apparently if you drilled a hole through the Earth and dropped something in it would accelerate to the middle then decelerate as it traversed the centre and then would arrive out the other side exactly 42 minutes later. Well fancy that, eh. But Cockneys? You threw me a curve ball there. But I choose to believe Douglas Adams, who said it’s just a number. He says he wanted a simple nondesrcipt number, looked out at his garden as he was writing and thought “42. That’ll do”. I believe the man. Still, I wonder what craziness the hen’s brain came up with though, but I expect James is at this very moment chuckling over an email that says “42? Not got a clue. Not even a Scooby Do. But don’t tell Androo”
Andrew,
I think you, and I, will be disappointed with the answer to 42.
As regards the dropping something through the earth. There is friction to take into account and I doubt it would reach the other side, just a slowly reducing back and forward till it vapourised. So no getting our Australian cousins to send guns for the fight.
Ah but we are allowed to imagine cooling the tube Lord T, and sucking out the air to make a vacuum, this being a thought experiment only. Tell Richard Branson though, and he’ll have plans for the 42 minute Virgin Earth Central Line London to Australia trip on the drawing board by tomorrow. Only problem is he’d end up in the ocean somewhere near New Zealand, still, that’s about as close as RyanAir got me to Paris
Cool,
I always thought (lol) that a thought experiment without the experiment was just a thought. And with thoughts you can do anything.
So in the spirit of that I propose that inmy thoughts the object dropped is Gordo.
Bugger I was looking forward to a new smugging method.
Gordon would be good, and the best bit is that so long as there was nobody at the other end to catch him (why would there be?) and the tube was wide enough to prevent him from crawling out as he momentarily stopped (we’d make sure of that in the design) he’d just keep oscillating backward and forward from hemisphere to hemisphere forever. Come to think of it. Could we fit the entire Palace of Westminster into this thing? Amazing what inspiration you can come up with while pondering the nondescript number 42.
Hmm, re-read all the hints, and the solution is quite simple btw, nothing high falutin’ (hey, I’m a hen of very little brain after all, what what do I know?)
Ok.. just for you here is another hint 4: Adams was kind of right.
Grace period before you have to join MENSA: 42 days.
muhahaha!
(When are you ready for that cool somali cruise we won from James btw?
What on earth is going on here?
[...] By the way, I wonder what’s going on here. [...]
James: I don’t know. I give up.
Fat Hen: I don’t know. I give up.
*pouts*
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