Stats/Maths Question

[Elixir]

When I was at university, such sloppy language will lose you marks.

At least 10% definitely had all ingredients.

Not 10% definitely had all ingredients.

No. Anything over 10% is not definite, it starts to come down to probability. You can't say 'at least' 10% definitely had all ingredients, because that implies that 15% could have definitely had all ingredients. Only 10% definitely had all ingredients.

EDIT for simpler clarification.
These are both correct:
At least 10% had all ingredients.
10% definitely had all ingredients.

But you can't combine the two:
At least 10% definitely had all ingredients.

 

[Reaper 392]

The easiest way I can see to do this, if you ignore the fact that they are missing bacon and whatever, is to start by working out the percentage of people who didn't have one of the items item, because the question is asking you for the minimum percentage of people that could have had an English breakfast for those percentages to work out. Then you can sign each percentage of the population with the 'I have not eaten x' label.

That gives you 30% without beans 25% without eggs, 20% without sausages and 15% without toast. To get the minimum people that could have had a full English, you want the maximum number of people missing one item, so ideally you will assign one missing item to each percentage of the population. To do this simply add up the percentages:

30% + 25% + 20% + 15% = 90%.

This leaves 10% who must have had all four ingredients. it is very likely that it will be more, but this is the absolute minimum number who have had a full english, so you can say that 10% definitely had a full english


No idea about how many spilled beans down their shirt

*edit*
Wow I type slow. It was only on the 8th post when i started

 

[muon]

No. Anything over 10% is not definite, it starts to come down to probability. You can't say 'at least' 10% definitely had all ingredients, because that implies that 15% could have definitely had all ingredients. Only 10% definitely had all ingredients.

Yep, that does sound right actually. I suppose it isn't sloppy at all then.

 

[moogle]

70%?

That's the lowest amount I can see where they would have had each item.
Don't know about beans down their shirt though.

 

[SpeedFreak]

At least 10% definitely had all ingredients.

This is an oxymoron.

 

[Amleto]

So basically 100 - 90 = 10 (90 is the total of 30 + 25 + 20 + 15)

The word definitely is in the question.



Yup.

The easiest way I can see to do this, if you ignore the fact that they are missing bacon and whatever, is to start by working out the percentage of people who didn't have one of the items item, because the question is asking you for the minimum percentage of people that could have had an English breakfast for those percentages to work out. Then you can sign each percentage of the population with the 'I have not eaten x' label.

That gives you 30% without beans 25% without eggs, 20% without sausages and 15% without toast. To get the minimum people that could have had a full English, you want the maximum number of people missing one item, so ideally you will assign one missing item to each percentage of the population. To do this simply add up the percentages:

30% + 25% + 20% + 15% = 90%.

This leaves 10% who must have had all four ingredients. it is very likely that it will be more, but this is the absolute minimum number who have had a full english, so you can say that 10% definitely had a full english


No idea about how many spilled beans down their shirt

*edit*
Wow I type slow. It was only on the 8th post when i started

let me ask you guys this:

If the question was restated with these figures

If 70% of people on this train had beans this morning, 70% had eggs, 70% had sausages and 70% had toast, ...

then don't you start to look rather silly!?

So basically 100 - 120 = -20 (120 is the total of 30 + 30 + 30 + 30)

 

[Helios1234]

Surely it just means that the minimum that have all 4 is zero, as in it is possible that no one had all 4 ingredients, whereas previously at least 10% must have had all 4.

 

[Elixir]

then don't you start to look rather silly!?

No, it just means it's possible that no-one had all 4 ingredients. You look silly.

 

[semi-pro waster]

You could just take a look at Join Dave, there's more of the puzzles and you can either try them or find the answers as well.