Any probability experts/actuaries out there? Problem inside.

[betty swollocks]

At work I have to do e-learning. Read something on the computer and then answer some questions. It's pathetic really, a virtually futile exercise in box ticking, but it's mandatory, so it has to be done.
One of the questions involves sliding all the correct answers into a box and only when all correct answers are in the box, do you get the question right. Get it wrong and the computer doesn't say no, it tells you 'that's partially correct' instead, so you then have to repeat not only that question, but the entire module again. You can go round and round in circles......as I have been doing. I know all the other correct answers off by heart.
This particular question has eight 'answers' to slide into the box: the trouble is is that you're not told how many of them are correct. All I know is is that by sliding all eight answers into the box I get the response 'that's partially correct' - so one or more is wrong. You are not told how many. I've also tried sliding all the answers singly into the box without success - so there is more than one correct answer.
No amount of reading of the actual e-learning helps. The answers (the ones to slide into the box) are so vague and ambiguous.
So here's my question: what are the chances of my randomly hitting on the correct answer ie sliding the correct number of correct answers into the box and thus getting my desired answer from the computer: 'yes, that's correct'?

 

[jonny jeez]

1 in 23,068.67

 

[jonny jeez]

or 1 in 184,549...I may have missed a multiplication there somewhere.

 

[marinyork]

You need the choose function on your calculator (where available).
8 choose 0 = 1
8 choose 1 = 8
8 choose 2 = 28
8 choose 3 = 56
8 choose 4 = 70
8 choose 5 = 56
8 choose 6 = 28
8 choose 7 = 8
8 choose 8 =1
We can discount 8Cr8 and 8Cr0.

 

[Scruffmonster]

First up, That sounds like a quite ridiculous system. I'd lodge a complaint.

Has Google not helped? Or a colleague?

Also, are there any answers that you can rule out with common sense? Surely all 8 cannot seem correct?

 

[Fnaar]

Sounds like a particularly poorly designed e-learning thingummyjig. Is there any chance you could canvas opinion from the others at work who have to suffer the tedium of the go through the e-learning, see if everyone is having problems then write to the 'providers'?*

*give them a range of possiblities... e.g. "our complaint can be ascertained from these words, some of which do not form part of it... slide these words randomly into this feckin' box till your eyes glaze over, and you may have worked it out."

 

[marinyork]

By the way does it matter which order you have the answers in, are there eight distrinct answers or just true/false or some have the same answers? If 8 distinct answers there would be 8x7x6x5x4x3x2x1 ways of arranging them. If true/false you can use what I said above or if some share the same answer.

 

[ohnovino]

Not sure I'm understanding this right, but if each slider has two positions then there are 2^8=256 combinations. As you've said there's more than one right answer, we can ignore 9 combinations (0 answers, and the 8 ways of having 1 answer) so that leaves 247.

 

[betty swollocks]

By the way does it matter which order you have the answers in, are there eight distrinct answers or just true/false or some have the same answers? If 8 distinct answers there would be 8x7x6x5x4x3x2x1 ways of arranging them. If true/false you can use what I said above or if some share the same answer.

No, no particular order.

 

[buddha]

I'd ask somebody else for the answer, as it seems like a waste of time. Maybe that question is a test of your patience.
Is it online, and is there a way of cheating?

 

[betty swollocks]

I'd ask somebody else for the answer, as it seems like a waste of time. Maybe that question is a test of your patience.
Is it online, and is there a way of cheating?

There is a way of cheating: it's called getting to answer from one of my colleagues. You see, they've all passed because someone somewhere at some time hit upon the right number and combination of answers and passed it on.
I want to get there under my own steam.... and make a point with our training dept about how pathetic and worthless their e-learning is.
btw: The e-learning website is the only website I've come across ever which is not compatible with mac computers. I only found this out by asking the training dept why nothing happened when I tried to log in at home!

 

[marinyork]

No, no particular order.

So, true/false and eight different answers? So if you think three answers are correct you slide those 3 into the box? In which case you have 28 combinations for 2 correct answers, 56 for 3 etc, 70 for 4 true answers out of eight etc. So that'd be about 0.4% chance of getting it right. If it is not true/false and there isn't some sharing of answers you have big problems!

 

[betty swollocks]

First up, That sounds like a quite ridiculous system. I'd lodge a complaint.

Has Google not helped? Or a colleague?

Also, are there any answers that you can rule out with common sense? Surely all 8 cannot seem correct?

I've tried eliminating some of the answers by 'common sense', but all the answers seem so viable because they are so vague and ambiguous.

 

[Scruffmonster]

There is a way of cheating: it's called getting to answer from one of my colleagues. You see, they've all passed because someone somewhere at some time hit upon the right number and combination of answers and passed it on.
I want to get there under my own steam.... and make a point with our training dept about how pathetic and worthless their e-learning is

This is very silly.

Just get the answers. It's badly designed whether you get there quick or slow. You're not proving anything and the only time you're wasting is your own.

 

[srw]

Not sure I'm understanding this right, but if each slider has two positions then there are 2^8=256 combinations. As you've said there's more than one right answer, we can ignore 9 combinations (0 answers, and the 8 ways of having 1 answer) so that leaves 247.

The problem isn't quite stated unambiguously, but on the basis of the information available I'd go for this interpretation - and we also know that we can ignore the combination of "all 8 answers". That leaves a chance of 246, or a probability of 0.4%.

But then you don't really need an actuary, you need someone who can do sums with probability.

I also agree with scruffmonster.