document.write( "Question 812706: The food you buy for your 15-horse herd lasts for 10 days. If you get 5 more horses, how long will that same amount of food last? (assume each horse eat about the same amount, I know this isn't true, but it's a good approximation given we don’t have any other information about the herd) \n" ); document.write( "

Algebra.Com's Answer #489267 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
Let $\"+x+\"$ = the 10 day supply of food for 15 horses
\n" ); document.write( " $\"+x%2F15+\"$ = the amount of food per horse for 10 days
\n" ); document.write( "-------------
\n" ); document.write( " $\"+15+%2B+5+=+20+\"$ horses now
\n" ); document.write( "Now the same amount of food means
\n" ); document.write( " $\"+x%2F20+\"$ is the amount of food per horse
\n" ); document.write( "-------------
\n" ); document.write( "Let $\"+d+\"$ = number of days the same
\n" ); document.write( "amount of food lasts
\n" ); document.write( "Now I can set up the ratio:
\n" ); document.write( " $\"+%28+x%2F15+%29+%2F+%28+x%2F20+%29+=+10%2Fd+\"$
\n" ); document.write( "------------------------
\n" ); document.write( " $\"+20%2F15+=+10%2Fd+\"$
\n" ); document.write( " $\"+20d+=+150+\"$
\n" ); document.write( " $\"+d+=+7.5+\"$
\n" ); document.write( "The same amount of food lasts 7.5 days\r
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