tricky maths

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aaman1
Posts: 35
Joined: Wed May 25, 2011 11:36 pm

tricky maths

Post by aaman1 »

Hi
Can anyone help with this question.

36 posts were spaced evenly along a road 7km long. What was the distance in metres between each pair of posts?

Many thanks.
no_ball

Re: tricky maths

Post by no_ball »

7km is 7000 metres.
36 posts therefore 35 gaps, divide 7000 by 35 to get the distance
Guest55
Posts: 16254
Joined: Mon Feb 12, 2007 2:21 pm

Re: tricky maths

Post by Guest55 »

A diagram would help - think how many gaps there will be between 36 posts.

Hint - try a smaller number e.g. 5 posts

POST ......... POST ......... POST ......... POST ......... POST

get the idea? :D
Tree
Posts: 536
Joined: Mon Aug 31, 2009 7:19 pm
Location: bucks

Re: tricky maths

Post by Tree »

Aaaah guest55 I wish you had been my maths teacher :wink:
Tree
Posts: 536
Joined: Mon Aug 31, 2009 7:19 pm
Location: bucks

Re: tricky maths

Post by Tree »

Although the above method only works if you assume the posts are infinately thin otherwise you would have to express the answer in terms of post thickness=d(m) ie (7000-36d)/35
Guest55
Posts: 16254
Joined: Mon Feb 12, 2007 2:21 pm

Re: tricky maths

Post by Guest55 »

It is a poorly worded question because you have to assume that a post is at the beginning and end of the distance as well as dimension-less (or, as you say Tree, have no thickness).

Once you 'see' a question like this you use the correct number to divide by .... that's what learning Maths is about :D :D
no_ball

Re: tricky maths

Post by no_ball »

I am a bit lost here, was my answer incorrect?
mystery
Posts: 8927
Joined: Tue Jul 21, 2009 10:56 pm

Re: tricky maths

Post by mystery »

No, but you forgot to use the phrase "a diagram would help" :D
no_ball

Re: tricky maths

Post by no_ball »

Thanks mystery, sometimes forget parents need tutoring first :lol: :lol: :lol:
Guest55
Posts: 16254
Joined: Mon Feb 12, 2007 2:21 pm

Re: tricky maths

Post by Guest55 »

no_ball - your post told the OP what to do but would not help in tackling another such question. Understanding and 'seeing' the question is more important ...
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