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July 4th, 2018, 08:34 AM   #11
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You forgot the 5th line:
Quote:
Originally Posted by skipjack View Post
Every cow was Kung Fu grazing,
Those cattle were faster than lightning!
In fact, it was a little bit frightening...
But they mowed with expert timing!
The field is now a green for putting!
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July 13th, 2018, 10:20 AM   #12
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Quote:
Originally Posted by Ganesh Ujwal View Post
100 cows can graze a field completely in 15 days, while 60 cows can do it in 30 days. How many cows are needed to do it in 10 days?

Answer is 140 cows

I tried: It'd seem like it'd only take 50 cows to graze a field in 30 days if 100 can do it in 15. But in question it shows 60 cows can do it in 30 days. I am confused with this question.
That would be true if the relationship were a simple proportion. In order to solve this you have to have some notion of what kind of function there is here. Since a simple proportion does not work, the next simpler function would be linear. There exist a unique linear function that gives those two data points and that is what I would be inclined to use, but that does not give "140 cows"!

Last edited by skipjack; July 14th, 2018 at 02:06 AM.
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July 13th, 2018, 11:14 AM   #13
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Consider a spherical cow.
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July 13th, 2018, 11:36 AM   #14
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July 14th, 2018, 02:08 AM   #15
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Quote:
Originally Posted by Country Boy View Post
That would be true if the relationship were a simple proportion.
No, it would need to be a simple inverse proportion,
i.e. (number of cows) = k/(number of days), where k is a constant.

Quote:
Originally Posted by Country Boy View Post
Since a simple proportion does not work, the next simpler function would be linear. There exist a unique linear function that gives those two data points and that is what I would be inclined to use, but that does not give "140 cows"!
Modifying the simple inverse proportion by using

(number of cows) = k/(number of days) + p, where k and p are constants,

implies a unique solution, namely k = 1200 and p = 20.

Using those values and substituting number of days = 10,
one gets the expected answer that number of cows = 140.
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