document.write( "Question 1030225: Suppose you own a party bus and you book groups of 20 to 70 people for a day trip. The cost per person is $30 minus 25 cents for every ticket sold. If gas and other costs are $200, how many tickets should you sell to maximize your profit? \n" ); document.write( "
Algebra.Com's Answer #645153 by robertb(5830)\"\" \"About 
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Let x = # of tickets sold.
\n" ); document.write( "==> Total revenues = x(30 - 0.25x) and Total costs = 200\r
\n" ); document.write( "\n" ); document.write( "==> Total profits = \"x%2830+-+0.25x%29+-+200+=+-0.25x%5E2+%2B+30x+-200\"\r
\n" ); document.write( "\n" ); document.write( "Taking the derivative and equating to 0 to get the extreme value, \r
\n" ); document.write( "\n" ); document.write( "-0.5x + 30 = 0
\n" ); document.write( "==> x = 30/0.5 = 60\r
\n" ); document.write( "\n" ); document.write( "(The 2nd derivative p\" = -0.5 < 0, hence we are assured an absolute maximum.)\r
\n" ); document.write( "\n" ); document.write( "Therefore, he has to sell 60 tickets to maximize profits.
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