Math riddle

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musicman135798642

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Wondering what the answer to this would be??? Help ASAP would be greatly appreciated!!
Farmer Brown raises chickens and cows. There are 960 animal legs and 720 animal eyes. How many more chickens are there than cows?
 
120?

You can setup a system of two equations with two unknowns, or a matrix.
 
musicman135798642 said:
Wondering what the answer to this would be??? Help ASAP would be greatly appreciated!!
Farmer Brown raises chickens and cows. There are 960 animal legs and 720 animal eyes. How many more chickens are there than cows?
Click to expand...

One method of solution would be educated guess - check - new guess

since every animal has two eyes (unless mutated) - assume there are 180 chickens and 180 cows.

There would be (180*6 = )1080 LEGS.

We need less legs - so we need toreplace cows with chickens. For 1 cow replaced with 1 chicken - we decrease 2 legs. We need to decrease (1080-960=)120 legs.

How many cows need to be replaced with chickens?
 
(just finished my time in the corner!)
So we got 360 animals as per Sir Khan...
x = cows ; since we got 960 legs:
4x + 2(360 - x) = 960
x = 120 : 120 milkers, 240 eggers !
 
Denis said:
(just finished my time in the corner!)
So we got 360 animals as per Sir Khan...
x = cows ; since we got 960 legs:
4x + 2(360 - x) = 960
x = 120 : 120 milkers, 240 eggers !
Click to expand...

I did

2x + 4y = 960
2x + 2y = 720
 
We were talking about defining your x's and y's.
 
warwick said:
Subhotosh Khan said:
We were talking about defining your x's and y's.
Click to expand...

Oh, I know. I thought it could be easily deduced.
Click to expand...

You don't get credit for what you think we can deduce. If this were a quiz or test question,
where there is partial credit, for instance, you would automatically get points deducted
for your set-up. You don't get the benefit of the doubt. You have to justify why you are
using those variables, which includes the real world limitations of their values, as well
as the names they represent.
 
lookagain said:
warwick said:
Subhotosh Khan said:
We were talking about defining your x's and y's.
Click to expand...

Oh, I know. I thought it could be easily deduced.
Click to expand...

You don't get credit for what you think we can deduce. If this were a quiz or test question,
where there is partial credit, for instance, you would automatically get points deducted
for your set-up. You don't get the benefit of the doubt. You have to justify why you are
using those variables, which includes the real world limitations of their values, as well
as the names they represent.
Click to expand...

I'm well aware of partial credit protocol.

Fortunately, this isn't an exam.
 
warwick said:
[The definition of my symbols is] not overly obvious?

Yes
Click to expand...

Denis previously defined x as the number of cows. Your system implies that x represents the number of chickens.

There is nothing wrong with forging your own path, but we like to know basic things upfront.

It's good form to always define your symbols because explicit definitions preclude the need for people to waste time confirming your intent.

 
Re:

mmm4444bot said:
warwick said:
[The definition of my symbols is] not overly obvious?

Yes
Click to expand...

Denis previously defined x as the number of cows. Your system implies that x represents the number of chickens.

There is nothing wrong with forging your own path, but we like to know basic things upfront.

It's good form to always define your symbols because explicit definitions preclude the need for people to waste time confirming your intent.
Click to expand...

My apologies. I forget I'm around mathematicians here. I'm used to being around physics guys. Haha. And you know how lax they are with their mathematics. :p :p
 
warwick said:
I'm well aware of partial credit protocol.

Fortunately, this isn't an exam.
Click to expand...

We are well aware of the fact that this isn't an exam....

However, when we answer a question - we need to "represent" best practices to the student (who can then emulate our "behavior"). And the best practice includes defining your variables.
 
Re: Re:

warwick said:
mmm4444bot said:
warwick said:
[The definition of my symbols is] not overly obvious?

Yes
Click to expand...
Click to expand...

\(\displaystyle > \ > \ >\)]My apologies. I forget I'm around mathematicians here. I'm used to being around physics guys. Haha.
And you know how lax they are with their mathematics. :p :p\(\displaystyle \ \ < \ < \ <\)
Click to expand...

No, I *never* would imagine that physicists would be lax in showing their work. They define their variables too.
And, were not going to compare this required shown work to that of the *alleged* physicists' amount of shown,
anyway. We look are to look at the merits of this problem. To do otherwise is excuse making.
 
I never said physicists don't define their variables.

I put down the correct system of equations and you people bitch about not defining my variables.

What if I wanted the OP to figure that out for himself and learn something? That really was why I left it out.
 
What's the big deal anyway?
Warwick, just say: "I'm deeply sorry, please forgive me; I promise to always declare my variables in the future..." :wink:
 


Physicists and engineers are to "pure" mathematics what firemen are to Swiss watchmaking. :twisted:



(Preemptive: I wrote "firemen" for a reason.)
 
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