The cost of cleaning up pollution in a stream is given by C=42000/(100-p), where C is the cost in dollars to clean p percent of the stream. (For instance, when p is 20, then the formula will calculate the cost to clean up 20 percent of the stream.)
a. Find the cost of cleaning up 40% of the stream.
b. What percent can be cleaned up for $1100
c. p must be greater than or equal to zero and p must be less than what number? Why?