Math Is Fun Forum

bilat

Member

Registered: 2008-04-23

Posts: 4

Hard

Please help me with this question

10 = e + f

E is more than F

What else can you say about E?

Thanks

simron

Real Member

Registered: 2006-10-07

Posts: 237

Re: Hard

So 10=e+f and e>f. Let's focus on the first one. The pairs for e and f can be:
0,10
1,9
2,8
3,7
4,6
5,5
6,4
7,3
8,2
9,1
10,0
But since e>f, those pairs are not valid until e>5. So e>5.
EDIT: I'm assuming that he needs this to work for all real numbers. My working still works, though.

Last edited by simron (2008-06-21 03:59:41)

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mathsyperson

Moderator

Registered: 2005-06-22

Posts: 4,900

Re: Hard

To make this work for the real numbers, rearrange the first equation to get f = 10-e, then use the inequality to say that e > 10-e.

That solves to give the same result as above.

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It wanted to be normal.