math

Math 1613 Homework #11

Name:

1. The level of contamination in a certain lake is

f(p) = √ p parts per million

when the population of the surrounding community is p people. The population of the surrounding community in year t is modeled as

p(t) − 400t2 + 2500 people

where t is the number of years since 2000. Write a single model that gives the level of contamination in year t.

2. Party Fun, Inc. manufactures and sells inflatable bounce toys of the type used at events such as festivals and children’s parties. The total cost to produce x moonwalk castles in a year is modeled as

C(x) = 600x + 90000 dollars.

The revenue from the sale of x moonwalk castles is modeled as

R(x) = 1800x dollars.

Write a single model that gives the profit from producing and selling x moonwalk castles.

3. A movie theater charges $9 for adults and $7 for seniors. On a particular day when 331 people paid an admission, the total receipts were $2517. Find how many of each type of ticket was sold. Use the substitution method.