document.write( "Question 969591: A harbor ferry service has about 240 000 riders per day for a fare of $2. The port authority wants to increase the fare to help with increasing operational costs. Research has shown that for every $0.10 increase in the fare the number of riders will drop by 10 000.\r
\n" ); document.write( "\n" ); document.write( "a)What increase in the fare will maximize the revenue?
\n" ); document.write( "b) what is the new fare?
\n" ); document.write( "c) what is the revenue that will be received from the new fare?
\n" ); document.write( "

Algebra.Com's Answer #592475 by ankor@dixie-net.com(22740)\"\" \"About 
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A harbor ferry service has about 240 000 riders per day for a fare of $2.
\n" ); document.write( " The port authority wants to increase the fare to help with increasing operational costs.
\n" ); document.write( " Research has shown that for every $0.10 increase in the fare the number of riders will drop by 10 000.
\n" ); document.write( ":
\n" ); document.write( "a)What increase in the fare will maximize the revenue?
\n" ); document.write( "let x = no. of 10 cent increases and also = no. 10000 rider decreases
\n" ); document.write( "Revenue = riders * fare
\n" ); document.write( "r(x) = (240000 - 10000x)(2 + .10x)
\n" ); document.write( "FOIL
\n" ); document.write( "r(x) = 480000 + 24000x - 20000x - 1000x^2
\n" ); document.write( "r(x) = -1000x^2 + 4000x + 480000
\n" ); document.write( "simplify, divide by 1000
\n" ); document.write( "r(x) = -x^2 + 4x + 480
\n" ); document.write( "The axis of symmetry will give us max revenue; x = -b/2a
\n" ); document.write( "x = -4/(2*-1)
\n" ); document.write( "x = 2 fare increases of $.10
\n" ); document.write( ":
\n" ); document.write( "b) what is the new fare?
\n" ); document.write( "2 + 2(.10) = $2.20 is the new fare
\n" ); document.write( ":
\n" ); document.write( "c) what is the revenue that will be received from the new fare?
\n" ); document.write( "(240000 - 2(10000)) * $2.20 = $484,000
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