document.write( "Question 459575: Please help me solve this problem. The Davis Company manufactures a product that has a unit selling price of $20 and a unit cost of $15. If fixed costs are $600,000 , determine the least number of units that must be sold for the company to have a profit. \n" ); document.write( "
| Algebra.Com's Answer #315139 by math-vortex(648)     You can put this solution on YOUR website! The big idea we will use to solve this problem is that the Davis Company will make a profit when their income exceeds their expenses.\r \n" ); document.write( "\n" ); document.write( "Let \n" ); document.write( "n = number of units sold \n" ); document.write( "I = income from selling n units \n" ); document.write( "E = expenses for selling n units\r \n" ); document.write( "\n" ); document.write( "We need two equations--one for income, one for expense--in terms of n\r \n" ); document.write( "\n" ); document.write( "--- \n" ); document.write( "INCOME is the number of units Davis sold times the selling price \n" ); document.write( "I = 20n \n" ); document.write( "--- \n" ); document.write( "EXPENSES are the fixed costs plus the number of units Davis sold times the unit cost \n" ); document.write( "E = 600,000 + 15n \n" ); document.write( "--- \n" ); document.write( "We want to know when income exceeds expenses. Here's how we say that mathematically: \n" ); document.write( "I > E \n" ); document.write( ". \n" ); document.write( "Now it's a simple matter of substituting the equivalent expressions we have for I and E. We get \n" ); document.write( "20n > 6000,000 + 15n \n" ); document.write( "' \n" ); document.write( "Solve for n to find the appropriate values for n \n" ); document.write( "20n - 15n > 500,000 \n" ); document.write( "5n > 600,000 \n" ); document.write( "n > 120,000\r \n" ); document.write( "\n" ); document.write( "We interpret this to mean that when n > 120,000, the income will exceed expenses. So, 120,001 is the least number of units Davis must sell to make a profit. \n" ); document.write( "--- \n" ); document.write( "CHECK \n" ); document.write( "It's always a good idea to check our answers. Substitute 120,000 for n in the income and expense equations. \n" ); document.write( "I = 20n = 20(120,000) = 2,400,000 \n" ); document.write( "E = 600,000 + 15n = 600,000 + 15(120,000) = 2,400,000\r \n" ); document.write( "\n" ); document.write( "We see that when Davis sells exactly 120,000 units, income and expense are equal. This is the break even point. \n" ); document.write( ". \n" ); document.write( "However, if Davis sells 120,001 units, look what happens: \n" ); document.write( "I = 20(120,010) = 2,400,020 \n" ); document.write( "E = 600,000 + 15(120,001) = 2,400,015\r \n" ); document.write( "\n" ); document.write( "The income is $5 more than the expenses. The Davis Company has made a profit. \n" ); document.write( " \n" ); document.write( " |