Summer Swimming Selection

Question

Summer Swimming Selection 
The municipal swimming pool in Nicetown has three different ways of paying for individual open swimming.  Evan is trying to decide which way to pay.
•	Early Pay:  Pay $45 before Memorial Day; swim any number of days
•	Deposit Plus:  $20 deposit plus $2.00 per day 
•	Daily Pay:  $3.50 per day

1.	 Write an equation for each situation such that the cost, y, of swimming is a function of the number of days swimming, x.  The ordered pairs will be in the form, (x, y), and you can write your equations in slope-intercept form.
a.	Early Pay:	
b.	Deposit Plus: 
c.	Daily Pay:

2.	Fill in the table with the costs of swimming the given number of days.
Table of swimming costs using the three different payment methods
Payment Method 	Number of days	0 days 	10 days	12 days	14 days	20 days
Early Pay					
Deposit Plus					
Daily Pay

3.	On your own (ungraded), graph each equation on the same set of axes so you can visually compare the payment methods.  Let the horizontal axis be the number of days swimming, x, and the vertical axis the cost in dollars, y.

Answer the following questions:

4.	If Evan goes swimming 10 times, which is the best payment method for him, and how much will he have to pay?

5.	If Evan goes swimming 12 times, which is the best method for him, and how much will he have to pay?

6.	If Evan goes swimming 14 times, which is the best method for him, and how much will he have to pay?

7.	If Evan doesn’t know how many times he will go swimming, which method do you think he should choose and why?

Can someone please fully explain what I need to do for this project? I really need help. Thanks guys

Ms. Sue · Answer

http://www.jiskha.com/display.cgi?id=1343833685

Steve · Answer

OK. we have

a. Early Pay: y = 45.00
b. Deposit Plus: y = 20.00+2.00x
c. Daily Pay: y = 3.50x

Your table should look something like this:

days: 0 10 12 14 20
a. 45 45 45 45 45
b. 20 40 44 48 60
c. 0 35 42 49 70

4. for n=10, Daily is the best (35)
5. for n=12, Daily is the best (42)
6. for n=14, Early is best (45)
7. Hard to say. If he only goes occasionally, then Daily is best. If he goes more than about 13 times, Early is best.