document.write( "Question 277463: Please help me solve this problem: Suppose you have a lemonade stand, and when you charge $2 per cup of lemonade you sell 120 cups. But when you raise your price to $3 you only sell 60 cups. Write an equation for the number of cups you sell as a function of the price you charge. Denote \"C\" for the number of cups, and \"P\" for the price you charge. Assume the function is linear.
\n" ); document.write( "Continuing our lemonade stand question:
\n" ); document.write( "We all know that local revenue (TR) is a function of the price we charge (P) multiplied by the item quantity sold (in our case-Cups),i.,e.,TR=Price*Cups.
\n" ); document.write( "Please write the equation for your TR by inputting your answer from the function you have calculated. What price would you maximize your TR?
\n" ); document.write( "

Algebra.Com's Answer #201992 by stanbon(75887)\"\" \"About 
You can put this solution on YOUR website!
Suppose you have a lemonade stand, and when you charge $2 per cup of lemonade you sell 120 cups. But when you raise your price to $3 you only sell 60 cups. Write an equation for the number of cups you sell as a function of the price you charge. Denote \"C\" for the number of cups, and \"P\" for the price you charge. Assume the function is linear.
\n" ); document.write( "-----
\n" ); document.write( "You have two points relating price and cups sold: (2,120) and (3,60)
\n" ); document.write( "Equation you want: C = mp + b where p is price and C is # of cups.
\n" ); document.write( "---
\n" ); document.write( "slope = m = (120-60)/(2-3) = -60
\n" ); document.write( "---
\n" ); document.write( "60 = -60*3 + b
\n" ); document.write( "b = 4*60
\n" ); document.write( "b = 240
\n" ); document.write( "-------------------
\n" ); document.write( "Equation: # of cups sold = -60p + 240
\n" ); document.write( "---------------------\r
\n" ); document.write( "\n" ); document.write( "Continuing our lemonade stand question:
\n" ); document.write( "We all know that local revenue (TR) is a function of the price we charge (P) multiplied by the item quantity sold (in our case-Cups),i.,e.,TR=Price*Cups.
\n" ); document.write( "Please write the equation for your TR by inputting your answer from the function you have calculated. What price would you maximize your TR?
\n" ); document.write( "--------------
\n" ); document.write( "Total Revenue = -60p^2 + 240p
\n" ); document.write( "--
\n" ); document.write( "This is a quadratic equation with a = -60 and b = 240
\n" ); document.write( "Maximum occurs when p = -b/2a = -240/(-120) = 2
\n" ); document.write( "----
\n" ); document.write( "Maximum sales occurs when the price is $2.
\n" ); document.write( "===============================================
\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
\n" ); document.write( "
\n" );