Special Assignment Game 4 - Off-season Break
Mid Semester Break
Pracalculus 64181 - Introduction to Exponentials
4.1 #11 Expanded Solution - To Be Discussed in Class

4.1 #11 Credit card balanced owed is $2000, monthly interest rate is 1.5 %,
and monthly minimum payment is 2.5 %. Before the end of each month

(a) Use a table showing minimum payment and interest to show balance through end of 12 months:
Month, t Balance, $, Bt

Bt = B0 (0.99)t

Interest, $, It

It = Bt (0.015) or

It = B0 (0.99)t x (0.015)

Minimum payment, $, 

Mt = Bt (0.025) or

Mt = B0 (0.99)t x (0.025)

t = 0, Jan B0 = 2000 I1 = 30 M1 = 50
t= 1 1980 29.7 49.5
2 1960.2 29.4 49.01
3 1940.59 29.11 48.51
4 1921.19 29.82 48.03
5 1901.98 28.53 47.55
6 1852.46 28.24 47.07
7 1864.13 27.96 46.6
8 1845.49 27.68 46.14
9 1827.03 27.41 45.68
10 1808.76 27.13 45.22
11 1790.67 26.86 44.77
t= 12 B12 = 1772.76 Sum = $340.84  

So Bt = B0 (0.99)t = 2000 (0.99) (From Series: B1= B0 + B0 (0.015) + B0( 0.025) )

It = B0 (0.99)t x (0.015) = 2000 (0.99)t ( 0.015)

Mt = B0 (0.99)t x (0.025)

(b) After one year unpaid balance is $1772.76.

You have paid $2000 - 1772.76 = $227.24

And total interest is the sum of interest column = $ 340.84
Balance for 48 mts Bt = B0 (0.99)t = 2000 (0.99)t

Interest and Payment Over 12 months