Question 1203900
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There are a lot of questions here. I'll focus on the first part only.


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Question:


Hak Young has accumulated some credit card debt while he was in college. His total debt is now $23,864.00 and his credit card charges 18% interest compounded monthly. He is getting worried about his debt and is determined to pay it off completely.
<font color=blue>What would Hak Young's minimum monthly payment have to be in order to pay off his debt in 5 years?</font>


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Effectively he is loaned $23,864.00 at an interest rate of 18% compounded monthly, and has a 5 year (or less) timeline.


Monthly payment formula
P = (L*i)/( 1-(1+i)^(-n) )
where,
P = monthly payment
L = loan amount
i = monthly interest rate in decimal form
n = number of months


For this problem:
P = unknown
L = 23864
i = 0.18/12 = 0.015 exactly
n = 5*12 = 60 months


So,
P = (L*i)/( 1-(1+i)^(-n) )
P = (23864*0.015)/( 1-(1+0.015)^(-60) )
P = 605.988752120533
P = <font color=red size=4>605.99 dollars</font> should be his minimum monthly payment. 


If he pays more than this per month, then he'll pay off the credit card debt sooner than 5 years.
Eg: if his payment is $701 per month, then he'll pay off the debt in about 4 years.


I'll let the student handle the other questions.
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