maths probability solution please

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idl
Posts: 16
Joined: Mon Oct 03, 2016 8:41 am

maths probability solution please

Post by idl »

Someone please help me how to solve this!!

i have 140 books. i find that 60% of the total number of books are paperbacks. the fiction books make up 0.3 of the total and 1/7 are by my favourite author.
How many books are likely to be paperback, non-fiction by my favourite author?


Thanks in advance.
Guest55
Posts: 16254
Joined: Mon Feb 12, 2007 2:21 pm

Re: maths probability solution please

Post by Guest55 »

idl wrote: i have 140 books. i find that 60% of the total number of books are paperbacks. the fiction books make up 0.3 of the total and 1/7 are by my favourite author.
How many books are likely to be paperback, non-fiction by my favourite author?
1/7 are by favourite author - 1/7 of 140 = 20

Can you complete it now?
idl
Posts: 16
Joined: Mon Oct 03, 2016 8:41 am

Re: maths probability solution please

Post by idl »

Hi
Thanks for the prompt reply.

I did that bit.
It said 60% paperback --- 84
0.3 of total are fiction --42
1/7 are fav --20

according to Question: likely to be paperback and non-fiction: 84+98(140-42!) by my fav author...dont know what to do after this...
Guest55
Posts: 16254
Joined: Mon Feb 12, 2007 2:21 pm

Re: maths probability solution please

Post by Guest55 »

I don't think you need to do this - the question is actually a bit vague.

If 0.3 are fiction then 0.7 are non-fiction.

So 20 x 0.7 = 14 would be my answer.
idl
Posts: 16
Joined: Mon Oct 03, 2016 8:41 am

Re: maths probability solution please

Post by idl »

:( ans was given as 8! Im struggling to fig this out :roll:
Guest55
Posts: 16254
Joined: Mon Feb 12, 2007 2:21 pm

Re: maths probability solution please

Post by Guest55 »

OK we need the paperback ones so we need to find 60% of 14 = 8.4!!

Very dodgy
idl
Posts: 16
Joined: Mon Oct 03, 2016 8:41 am

Re: maths probability solution please

Post by idl »

isn't it!! but options are whole numbers, no deci...
Guest55
Posts: 16254
Joined: Mon Feb 12, 2007 2:21 pm

Re: maths probability solution please

Post by Guest55 »

Someone has made a mistake with the question as the answer should be a whole number. Can you double check the numbers you posted?
ToadMum
Posts: 11945
Joined: Wed Jan 18, 2012 12:41 pm
Location: Essex

Re: maths probability solution please

Post by ToadMum »

Where on earth did this question come from? :roll:
Outside of a dog, a book is a man's best friend. Inside of a dog it's too dark to read.Groucho Marx
idl
Posts: 16
Joined: Mon Oct 03, 2016 8:41 am

Re: maths probability solution please

Post by idl »

I checked and read the question many times..this is from Bond 11+ test papers
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