Expert: Bobby Soltani - 7/20/2009

Question
Hi Bobby, I need help in solving this problem
The cost in millions of dollars, to remove x% of pollution in a lake modeled by C=6000
                      ______
                      200-2x
what is the cost to remove 75% of the pollutant. How do I work this out please provide an example or the work you used to solve the equation.
Thank you

Answer
Hi,
I couldn't tell exactly what your equation was supposed to look like because of the formatting, but I think it is the following:

C = 6000/(200-2x)

substitute 75 in for x since we want to determine the cost C to remove 75% (x = 75) of the pollutant

C = 6000/(200-2*75)

multiply 2 times 75

C = 6000/(200-150)

subtract 150 from 200

C = 6000/50

divide 6000 by 50

= 120

So, the cost is 120 million dollars. Let me know if you have any questions.

Bobby