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#1 2016-08-23 05:02:09

Mathegocart
Member
Registered: 2012-04-29
Posts: 2,226

Confirmation on problems

I was doing this triangle problem,
1) There are 3 angles in a triangle, a,b, and c. a < 40, b = c+1, and if c is an integer, what is the least possible value of c?

Is it 71?

2) 15. Let f(a,b) be defined as a^2+b^2-2,(where a and b are positive integers) which of the following CANNOT be the value of f(a,b)?
(a) 0
(b) 2
(c) 3
(d) 6
Is it 2?

3) In a store, 5 customers have bought 7 items, 11 people have bought 6 items, 14 people have bought 5 items, 60 people have bought 4 items, and 10 have bought fewer than 4 items(the number is not specifically known.), which information can be determined?
I. The average amount of items purchased per customer
II. Median number of items purchased per consumer
III. Mode of number of items purchased by consumer
Is it II and III?
4) Flipping y=3x-1 over the y axis obtains -3x-1. Right?

Last edited by Mathegocart (2016-08-23 06:02:09)


The integral of hope is reality.
May bobbym have a wonderful time in the pearly gates of heaven.
He will be sorely missed.

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#2 2016-08-23 05:34:09

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Confirmation on problems

Hi;



In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

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#3 2016-08-23 05:40:19

zetafunc
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Registered: 2014-05-21
Posts: 2,432
Website

Re: Confirmation on problems

For 2), I guess you want to say that
Just set f(x) = 0 in each of those four cases and see if you can find integer pairs a,b that make up that solution (there aren't that many cases to check in each case). Or you could use modulo, which seems excessive.

4) Flipping y=3x-1 over the y axis obtains -3x-1. Right?

Yes.

Last edited by zetafunc (2016-08-23 05:41:20)

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#4 2016-08-23 05:43:15

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Confirmation on problems

He should leave out the f(x). It has no meaning here.

It should be

2) 15. Let f(a,b) be defined as a^2+b^2-2, which of the following CANNOT be the value of f(a,b)?
(a) 0
(b) 2
(c) 3
(d) 6
Is it 2?

What kind of numbers are a and b? Integers? What other constraints are put on them?


In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

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#5 2016-08-23 05:45:57

zetafunc
Moderator
Registered: 2014-05-21
Posts: 2,432
Website

Re: Confirmation on problems

I agree, strange that that notation is used -- f(a,b) would be more appropriate, or just any random letter, or even nothing at all.

Last edited by zetafunc (2016-08-23 05:46:05)

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#6 2016-08-23 05:51:14

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Confirmation on problems

Hi Mathegocart;

Also, there has to be more constraints put on a and b. Are they integers? Positive integers?


In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

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#7 2016-08-23 06:02:57

Mathegocart
Member
Registered: 2012-04-29
Posts: 2,226

Re: Confirmation on problems

Silly mistake fixed, thanks to zetafunc for suggesting modulo.


The integral of hope is reality.
May bobbym have a wonderful time in the pearly gates of heaven.
He will be sorely missed.

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#8 2016-08-23 06:10:40

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Confirmation on problems

Okay, I see your corrections. Now the problem is solvable.



In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

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#9 2016-08-23 16:16:23

thickhead
Member
Registered: 2016-04-16
Posts: 1,086

Re: Confirmation on problems


{1}Vasudhaiva Kutumakam.{The whole Universe is a family.}
(2)Yatra naaryasthu poojyanthe Ramanthe tatra Devataha
{Gods rejoice at those places where ladies are respected.}

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