3 You realize that you have a 5000 balance on your credit ca
3. You realize that you have a $5000 balance on your credit card, which is being assessed 18% yearly interest. If you cut the credit card up and make $100 payments every month on it, how many years until you’ve paid it off?
Solution
Balance on credit card = $ 5,000
Interest rate = 18 % p.a. or 0.18/12 = 0.015 p.m.
Monthly interest amount = 0.15 x $ 5,000 = $ 75
Amount goes to principal = $ 100 - $ 75 = $ 25
Amortization schedule:
Month
Total Principal (P)
Interest(I)
Principal Paid (p = P - I)
Balance Principal
(P - p)
1
5000.00
75.00
25.00
4975.00
2
4975.00
74.63
25.38
4949.63
3
4949.63
74.24
25.76
4923.87
4
4923.87
73.86
26.14
4897.73
5
4897.73
73.47
26.53
4871.19
6
4871.19
73.07
26.93
4844.26
7
4844.26
72.66
27.34
4816.93
8
4816.93
72.25
27.75
4789.18
9
4789.18
71.84
28.16
4761.02
10
4761.02
71.42
28.58
4732.43
11
4732.43
70.99
29.01
4703.42
12
4703.42
70.55
29.45
4673.97
13
4673.97
70.11
29.89
4644.08
14
4644.08
69.66
30.34
4613.74
15
4613.74
69.21
30.79
4582.95
16
4582.95
68.74
31.26
4551.69
17
4551.69
68.28
31.72
4519.97
18
4519.97
67.80
32.20
4487.77
19
4487.77
67.32
32.68
4455.08
20
4455.08
66.83
33.17
4421.91
21
4421.91
66.33
33.67
4388.24
22
4388.24
65.82
34.18
4354.06
23
4354.06
65.31
34.69
4319.37
24
4319.37
64.79
35.21
4284.16
25
4284.16
64.26
35.74
4248.42
26
4248.42
63.73
36.27
4212.15
27
4212.15
63.18
36.82
4175.33
28
4175.33
62.63
37.37
4137.96
29
4137.96
62.07
37.93
4100.03
30
4100.03
61.50
38.50
4061.53
31
4061.53
60.92
39.08
4022.46
32
4022.46
60.34
39.66
3982.79
33
3982.79
59.74
40.26
3942.53
34
3942.53
59.14
40.86
3901.67
35
3901.67
58.53
41.47
3860.20
36
3860.20
57.90
42.10
3818.10
37
3818.10
57.27
42.73
3775.37
38
3775.37
56.63
43.37
3732.00
39
3732.00
55.98
44.02
3687.98
40
3687.98
55.32
44.68
3643.30
41
3643.30
54.65
45.35
3597.95
42
3597.95
53.97
46.03
3551.92
43
3551.92
53.28
46.72
3505.20
44
3505.20
52.58
47.42
3457.78
45
3457.78
51.87
48.13
3409.64
46
3409.64
51.14
48.86
3360.79
47
3360.79
50.41
49.59
3311.20
48
3311.20
49.67
50.33
3260.87
49
3260.87
48.91
51.09
3209.78
50
3209.78
48.15
51.85
3157.93
51
3157.93
47.37
52.63
3105.30
52
3105.30
46.58
53.42
3051.88
53
3051.88
45.78
54.22
2997.66
54
2997.66
44.96
55.04
2942.62
55
2942.62
44.14
55.86
2886.76
56
2886.76
43.30
56.70
2830.06
57
2830.06
42.45
57.55
2772.51
58
2772.51
41.59
58.41
2714.10
59
2714.10
40.71
59.29
2654.81
60
2654.81
39.82
60.18
2594.63
61
2594.63
38.92
61.08
2533.55
62
2533.55
38.00
62.00
2471.56
63
2471.56
37.07
62.93
2408.63
64
2408.63
36.13
63.87
2344.76
65
2344.76
35.17
64.83
2279.93
66
2279.93
34.20
65.80
2214.13
67
2214.13
33.21
66.79
2147.34
68
2147.34
32.21
67.79
2079.55
69
2079.55
31.19
68.81
2010.75
70
2010.75
30.16
69.84
1940.91
71
1940.91
29.11
70.89
1870.02
72
1870.02
28.05
71.95
1798.07
73
1798.07
26.97
73.03
1725.04
74
1725.04
25.88
74.12
1650.92
75
1650.92
24.76
75.24
1575.68
76
1575.68
23.64
76.36
1499.32
77
1499.32
22.49
77.51
1421.81
78
1421.81
21.33
78.67
1343.13
79
1343.13
20.15
79.85
1263.28
80
1263.28
18.95
81.05
1182.23
81
1182.23
17.73
82.27
1099.96
82
1099.96
16.50
83.50
1016.46
83
1016.46
15.25
84.75
931.71
84
931.71
13.98
86.02
845.68
85
845.68
12.69
87.31
758.37
86
758.37
11.38
88.62
669.74
87
669.74
10.05
89.95
579.79
88
579.79
8.70
91.30
488.49
89
488.49
7.33
92.67
395.82
90
395.82
5.94
94.06
301.75
91
301.75
4.53
95.47
206.28
92
206.28
3.09
96.91
109.37
93
109.37
1.64
98.36
11.01
94
11.01
0.17
99.83
-88.82
Hence it will take 94 months or 94/12 = 7.8 years to pay off the loan.
| Month | Total Principal (P) | Interest(I) | Principal Paid (p = P - I) | Balance Principal (P - p) |
| 1 | 5000.00 | 75.00 | 25.00 | 4975.00 |
| 2 | 4975.00 | 74.63 | 25.38 | 4949.63 |
| 3 | 4949.63 | 74.24 | 25.76 | 4923.87 |
| 4 | 4923.87 | 73.86 | 26.14 | 4897.73 |
| 5 | 4897.73 | 73.47 | 26.53 | 4871.19 |
| 6 | 4871.19 | 73.07 | 26.93 | 4844.26 |
| 7 | 4844.26 | 72.66 | 27.34 | 4816.93 |
| 8 | 4816.93 | 72.25 | 27.75 | 4789.18 |
| 9 | 4789.18 | 71.84 | 28.16 | 4761.02 |
| 10 | 4761.02 | 71.42 | 28.58 | 4732.43 |
| 11 | 4732.43 | 70.99 | 29.01 | 4703.42 |
| 12 | 4703.42 | 70.55 | 29.45 | 4673.97 |
| 13 | 4673.97 | 70.11 | 29.89 | 4644.08 |
| 14 | 4644.08 | 69.66 | 30.34 | 4613.74 |
| 15 | 4613.74 | 69.21 | 30.79 | 4582.95 |
| 16 | 4582.95 | 68.74 | 31.26 | 4551.69 |
| 17 | 4551.69 | 68.28 | 31.72 | 4519.97 |
| 18 | 4519.97 | 67.80 | 32.20 | 4487.77 |
| 19 | 4487.77 | 67.32 | 32.68 | 4455.08 |
| 20 | 4455.08 | 66.83 | 33.17 | 4421.91 |
| 21 | 4421.91 | 66.33 | 33.67 | 4388.24 |
| 22 | 4388.24 | 65.82 | 34.18 | 4354.06 |
| 23 | 4354.06 | 65.31 | 34.69 | 4319.37 |
| 24 | 4319.37 | 64.79 | 35.21 | 4284.16 |
| 25 | 4284.16 | 64.26 | 35.74 | 4248.42 |
| 26 | 4248.42 | 63.73 | 36.27 | 4212.15 |
| 27 | 4212.15 | 63.18 | 36.82 | 4175.33 |
| 28 | 4175.33 | 62.63 | 37.37 | 4137.96 |
| 29 | 4137.96 | 62.07 | 37.93 | 4100.03 |
| 30 | 4100.03 | 61.50 | 38.50 | 4061.53 |
| 31 | 4061.53 | 60.92 | 39.08 | 4022.46 |
| 32 | 4022.46 | 60.34 | 39.66 | 3982.79 |
| 33 | 3982.79 | 59.74 | 40.26 | 3942.53 |
| 34 | 3942.53 | 59.14 | 40.86 | 3901.67 |
| 35 | 3901.67 | 58.53 | 41.47 | 3860.20 |
| 36 | 3860.20 | 57.90 | 42.10 | 3818.10 |
| 37 | 3818.10 | 57.27 | 42.73 | 3775.37 |
| 38 | 3775.37 | 56.63 | 43.37 | 3732.00 |
| 39 | 3732.00 | 55.98 | 44.02 | 3687.98 |
| 40 | 3687.98 | 55.32 | 44.68 | 3643.30 |
| 41 | 3643.30 | 54.65 | 45.35 | 3597.95 |
| 42 | 3597.95 | 53.97 | 46.03 | 3551.92 |
| 43 | 3551.92 | 53.28 | 46.72 | 3505.20 |
| 44 | 3505.20 | 52.58 | 47.42 | 3457.78 |
| 45 | 3457.78 | 51.87 | 48.13 | 3409.64 |
| 46 | 3409.64 | 51.14 | 48.86 | 3360.79 |
| 47 | 3360.79 | 50.41 | 49.59 | 3311.20 |
| 48 | 3311.20 | 49.67 | 50.33 | 3260.87 |
| 49 | 3260.87 | 48.91 | 51.09 | 3209.78 |
| 50 | 3209.78 | 48.15 | 51.85 | 3157.93 |
| 51 | 3157.93 | 47.37 | 52.63 | 3105.30 |
| 52 | 3105.30 | 46.58 | 53.42 | 3051.88 |
| 53 | 3051.88 | 45.78 | 54.22 | 2997.66 |
| 54 | 2997.66 | 44.96 | 55.04 | 2942.62 |
| 55 | 2942.62 | 44.14 | 55.86 | 2886.76 |
| 56 | 2886.76 | 43.30 | 56.70 | 2830.06 |
| 57 | 2830.06 | 42.45 | 57.55 | 2772.51 |
| 58 | 2772.51 | 41.59 | 58.41 | 2714.10 |
| 59 | 2714.10 | 40.71 | 59.29 | 2654.81 |
| 60 | 2654.81 | 39.82 | 60.18 | 2594.63 |
| 61 | 2594.63 | 38.92 | 61.08 | 2533.55 |
| 62 | 2533.55 | 38.00 | 62.00 | 2471.56 |
| 63 | 2471.56 | 37.07 | 62.93 | 2408.63 |
| 64 | 2408.63 | 36.13 | 63.87 | 2344.76 |
| 65 | 2344.76 | 35.17 | 64.83 | 2279.93 |
| 66 | 2279.93 | 34.20 | 65.80 | 2214.13 |
| 67 | 2214.13 | 33.21 | 66.79 | 2147.34 |
| 68 | 2147.34 | 32.21 | 67.79 | 2079.55 |
| 69 | 2079.55 | 31.19 | 68.81 | 2010.75 |
| 70 | 2010.75 | 30.16 | 69.84 | 1940.91 |
| 71 | 1940.91 | 29.11 | 70.89 | 1870.02 |
| 72 | 1870.02 | 28.05 | 71.95 | 1798.07 |
| 73 | 1798.07 | 26.97 | 73.03 | 1725.04 |
| 74 | 1725.04 | 25.88 | 74.12 | 1650.92 |
| 75 | 1650.92 | 24.76 | 75.24 | 1575.68 |
| 76 | 1575.68 | 23.64 | 76.36 | 1499.32 |
| 77 | 1499.32 | 22.49 | 77.51 | 1421.81 |
| 78 | 1421.81 | 21.33 | 78.67 | 1343.13 |
| 79 | 1343.13 | 20.15 | 79.85 | 1263.28 |
| 80 | 1263.28 | 18.95 | 81.05 | 1182.23 |
| 81 | 1182.23 | 17.73 | 82.27 | 1099.96 |
| 82 | 1099.96 | 16.50 | 83.50 | 1016.46 |
| 83 | 1016.46 | 15.25 | 84.75 | 931.71 |
| 84 | 931.71 | 13.98 | 86.02 | 845.68 |
| 85 | 845.68 | 12.69 | 87.31 | 758.37 |
| 86 | 758.37 | 11.38 | 88.62 | 669.74 |
| 87 | 669.74 | 10.05 | 89.95 | 579.79 |
| 88 | 579.79 | 8.70 | 91.30 | 488.49 |
| 89 | 488.49 | 7.33 | 92.67 | 395.82 |
| 90 | 395.82 | 5.94 | 94.06 | 301.75 |
| 91 | 301.75 | 4.53 | 95.47 | 206.28 |
| 92 | 206.28 | 3.09 | 96.91 | 109.37 |
| 93 | 109.37 | 1.64 | 98.36 | 11.01 |
| 94 | 11.01 | 0.17 | 99.83 | -88.82 |



