Have you ever heard of Chamberlain's formula, which claims to be a model that tells you how many years you should drive your present car before you buy a new one? If y is this number of years, then Chamberlain's formula reads GMC (G - M)DP y = where G is the new car's gas mileage, M is your present car's gas mileage, C is the cost in dollars of the new car, D is the number of miles you drive in a year, and P is the dollar price of gasoline per gallon. Suppose the new car's gas mileage is 33 mi/gal, the old car's gas mileage is 13 mi/gal, the price of the new car is $30,000, you drive 15,000 mi/year, and the cost of gasoline is $5.00/gal. How many years should your old car have been driven to justify buying the new one?

A certain city's power company charges their residents for electricity usage on a daily basis. There is a basic charge of 11.57 cents. For each day the first 10 kWh cost 4.81 cents per kWh and any additional kWhs are 9.69 per kWh. (A kWh, or kilowatt-hour, is a unit of energy.) (a) Complete the following table using the information provided above. kWhkWh 0 5 10 15 20 cost (dollars)cost (dollars)           kWhkWh 25 30 35 40 cost (dollars)cost (dollars)         (b) We can define a piecewise function f(x)f(x) where xx is the kWh used in a day and f(x)f(x) is the cost, in dollars. This function would have the form   f(x)={g(x)h(x)ififx∈Ax∈Bf(x)={g(x)ifx∈Ah(x)ifx∈B What functions g(x)g(x) and h(x)h(x) make up the piecewise function f(x)f(x)? g(x)=g(x)= for A = h(x)=h(x)= for B = Hint: A and B are intervals. If an interval uses ±∞±∞ write inf or -inf . (c) Using the above function, what is the cost of 26 kWh? dollars. (d) For 3 dollars, what is the maximum kWh usage for one…

Question 10 (10 points) 4) Listen You purchased property 10 years ago for $15,000. Today that same property has a value of $27,000. What is the percentage change in the value of the properY? Use the New-Old equation/formula: x 100 to find the solution. Old O a) 80% O b) 44% c) 20% d) Not enough information is given to find a solution.

. In 1999 the world population hit 6 billion. In 2012 the world population hit 7 billion. Use the doubling formula to determine the doubling time of the world's population