In: Finance
Down Payment made by Sofie = 15% of $225,000 = $33,750
Remaining Loan = $225,000 - $33750 = $191,250
Let A be Loan Amount, D be discount factor or APR,r be periodic interest rate, n be Number of Periodic payments
D = {[(1 + r)^n] - 1} / [ r* (1 + r) ^ n]
n = 15 * 12 months = 180
r = APR/no of periods in a year = 3.5% /12 = 0.00291667
D = {[(1 + 0.002917)^180] -1}/[ 0.002917(1+0.002917) ^ 180] = 139.87
a) Loan Payment Monthly (P) = Loan Amount / Discount Factor = 191,250/139.88= 1367.25
b),c),d) are done below amortization table
Here is the Amortization Table
| Month | Payment | Interest | Pricipal Paid | Unpaid Balance | Cumulative Interest Paid Till Now | Cumulative Principal Paid Till now | 
| 0 | 191250 | |||||
| 1 | 1367.25 | 557.88 | 809.37375 | 190440.6263 | 557.87625 | 809.37375 | 
| 2 | 1367.25 | 555.52 | 811.7346932 | 189628.8916 | 1113.391557 | 1621.108443 | 
| 3 | 1367.25 | 553.15 | 814.1025233 | 188814.789 | 1666.539033 | 2435.210967 | 
| 4 | 1367.25 | 550.77 | 816.4772604 | 187998.3118 | 2217.311773 | 3251.688227 | 
| 5 | 1367.25 | 548.39 | 818.8589246 | 187179.4528 | 2765.702848 | 4070.547152 | 
| 6 | 1367.25 | 546 | 821.247536 | 186358.2053 | 3311.705312 | 4891.794688 | 
| 7 | 1367.25 | 543.61 | 823.6431151 | 185534.5622 | 3855.312197 | 5715.437803 | 
| 8 | 1367.25 | 541.2 | 826.0456821 | 184708.5165 | 4396.516515 | 6541.483485 | 
| 9 | 1367.25 | 538.79 | 828.4552573 | 183880.0613 | 4935.311258 | 7369.938742 | 
| 10 | 1367.25 | 536.38 | 830.8718613 | 183049.1894 | 5471.689397 | 8200.810603 | 
| 11 | 1367.25 | 533.95 | 833.2955145 | 182215.8939 | 6005.643882 | 9034.106118 | 
| 12 | 1367.25 | 531.52 | 835.7262375 | 181380.1676 | 6537.167645 | 9869.832355 | 
| 13 | 1367.25 | 529.09 | 838.164051 | 180542.0036 | 7066.253594 | 10707.99641 | 
| 14 | 1367.25 | 526.64 | 840.6089755 | 179701.3946 | 7592.894618 | 11548.60538 | 
| 15 | 1367.25 | 524.19 | 843.0610319 | 178858.3336 | 8117.083586 | 12391.66641 | 
| 16 | 1367.25 | 521.73 | 845.5202409 | 178012.8133 | 8638.813345 | 13237.18665 | 
| 17 | 1367.25 | 519.26 | 847.9866235 | 177164.8267 | 9158.076722 | 14085.17328 | 
| 18 | 1367.25 | 516.79 | 850.4602005 | 176314.3665 | 9674.866521 | 14935.63348 | 
| 19 | 1367.25 | 514.31 | 852.9409929 | 175461.4255 | 10189.17553 | 15788.57447 | 
| 20 | 1367.25 | 511.82 | 855.4290217 | 174605.9965 | 10700.99651 | 16644.00349 | 
| 21 | 1367.25 | 509.33 | 857.9243082 | 173748.0722 | 11210.3222 | 17501.9278 | 
| 22 | 1367.25 | 506.82 | 860.4268734 | 172887.6453 | 11717.14533 | 18362.35467 | 
| 23 | 1367.25 | 504.31 | 862.9367386 | 172024.7086 | 12221.45859 | 19225.29141 | 
| 24 | 1367.25 | 501.8 | 865.4539251 | 171159.2547 | 12723.25466 | 20090.74534 | 
| 25 | 1367.25 | 499.27 | 867.9784542 | 170291.2762 | 13222.52621 | 20958.72379 | 
| 26 | 1367.25 | 496.74 | 870.5103473 | 169420.7659 | 13719.26586 | 21829.23414 | 
| 27 | 1367.25 | 494.2 | 873.049626 | 168547.7162 | 14213.46623 | 22702.28377 | 
| 28 | 1367.25 | 491.65 | 875.5963117 | 167672.1199 | 14705.11992 | 23577.88008 | 
| 29 | 1367.25 | 489.1 | 878.1504262 | 166793.9695 | 15194.2195 | 24456.0305 | 
| 30 | 1367.25 | 486.54 | 880.711991 | 165913.2575 | 15680.75751 | 25336.74249 | 
| 31 | 1367.25 | 483.97 | 883.2810279 | 165029.9765 | 16164.72648 | 26220.02352 | 
| 32 | 1367.25 | 481.39 | 885.8575586 | 164144.1189 | 16646.11892 | 27105.88108 | 
| 33 | 1367.25 | 478.81 | 888.4416051 | 163255.6773 | 17124.92731 | 27994.32269 | 
| 34 | 1367.25 | 476.22 | 891.0331893 | 162364.6441 | 17601.14412 | 28885.35588 | 
| 35 | 1367.25 | 473.62 | 893.6323331 | 161471.0118 | 18074.76179 | 29778.98821 | 
| 36 | 1367.25 | 471.01 | 896.2390586 | 160574.7727 | 18545.77273 | 30675.22727 | 
| 37 | 1367.25 | 468.4 | 898.8533879 | 159675.9193 | 19014.16934 | 31574.08066 | 
| 38 | 1367.25 | 465.77 | 901.4753433 | 158774.444 | 19479.944 | 32475.556 | 
| 39 | 1367.25 | 463.15 | 904.1049468 | 157870.3391 | 19943.08905 | 33379.66095 | 
| 40 | 1367.25 | 460.51 | 906.742221 | 156963.5968 | 20403.59683 | 34286.40317 | 
| 41 | 1367.25 | 457.86 | 909.387188 | 156054.2096 | 20861.45965 | 35195.79035 | 
| 42 | 1367.25 | 455.21 | 912.0398705 | 155142.1698 | 21316.66978 | 36107.83022 | 
| 43 | 1367.25 | 452.55 | 914.7002908 | 154227.4695 | 21769.21948 | 37022.53052 | 
| 44 | 1367.25 | 449.88 | 917.3684715 | 153310.101 | 22219.10101 | 37939.89899 | 
| 45 | 1367.25 | 447.21 | 920.0444353 | 152390.0566 | 22666.30658 | 38859.94342 | 
| 46 | 1367.25 | 444.52 | 922.728205 | 151467.3284 | 23110.82837 | 39782.67163 | 
| 47 | 1367.25 | 441.83 | 925.4198031 | 150541.9086 | 23552.65857 | 40708.09143 | 
| 48 | 1367.25 | 439.13 | 928.1192527 | 149613.7893 | 23991.78932 | 41636.21068 | 
| 49 | 1367.25 | 436.42 | 930.8265766 | 148682.9627 | 24428.21274 | 42567.03726 | 
| 50 | 1367.25 | 433.71 | 933.5417977 | 147749.4209 | 24861.92094 | 43500.57906 | 
| 51 | 1367.25 | 430.99 | 936.2649391 | 146813.156 | 25292.906 | 44436.844 | 
| 52 | 1367.25 | 428.25 | 938.9960239 | 145874.16 | 25721.15998 | 45375.84002 | 
| 53 | 1367.25 | 425.51 | 941.7350753 | 144932.4249 | 26146.6749 | 46317.5751 | 
| 54 | 1367.25 | 422.77 | 944.4821166 | 143987.9428 | 26569.44279 | 47262.05721 | 
| 55 | 1367.25 | 420.01 | 947.2371709 | 143040.7056 | 26989.45562 | 48209.29438 | 
| 56 | 1367.25 | 417.25 | 950.0002617 | 142090.7054 | 27406.70535 | 49159.29465 | 
| 57 | 1367.25 | 414.48 | 952.7714125 | 141137.9339 | 27821.18394 | 50112.06606 | 
| 58 | 1367.25 | 411.7 | 955.5506467 | 140182.3833 | 28232.8833 | 51067.6167 | 
| 59 | 1367.25 | 408.91 | 958.3379879 | 139224.0453 | 28641.79531 | 52025.95469 | 
| 60 | 1367.25 | 406.12 | 961.1334598 | 138262.9118 | 29047.91185 | 52987.08815 | 
| 61 | 1367.25 | 403.31 | 963.9370861 | 137298.9748 | 29451.22476 | 53951.02524 | 
| 62 | 1367.25 | 400.5 | 966.7488906 | 136332.2259 | 29851.72587 | 54917.77413 | 
| 63 | 1367.25 | 397.68 | 969.5688971 | 135362.657 | 30249.40697 | 55887.34303 | 
| 64 | 1367.25 | 394.85 | 972.3971296 | 134390.2598 | 30644.25984 | 56859.74016 | 
| 65 | 1367.25 | 392.02 | 975.233612 | 133415.0262 | 31036.27623 | 57834.97377 | 
| 66 | 1367.25 | 389.17 | 978.0783685 | 132436.9479 | 31425.44786 | 58813.05214 | 
| 67 | 1367.25 | 386.32 | 980.9314231 | 131456.0164 | 31811.76644 | 59793.98356 | 
| 68 | 1367.25 | 383.46 | 983.7928 | 130472.2236 | 32195.22364 | 60777.77636 | 
| 69 | 1367.25 | 380.59 | 986.6625236 | 129485.5611 | 32575.81112 | 61764.43888 | 
| 70 | 1367.25 | 377.71 | 989.5406182 | 128496.0205 | 32953.5205 | 62753.9795 | 
| 71 | 1367.25 | 374.82 | 992.4271082 | 127503.5934 | 33328.34339 | 63746.40661 | 
| 72 | 1367.25 | 371.93 | 995.3220181 | 126508.2714 | 33700.27137 | 64741.72863 | 
| 73 | 1367.25 | 369.02 | 998.2253724 | 125510.046 | 34069.296 | 65739.954 | 
| 74 | 1367.25 | 366.11 | 1001.137196 | 124508.9088 | 34435.4088 | 66741.0912 | 
| 75 | 1367.25 | 363.19 | 1004.057513 | 123504.8513 | 34798.60129 | 67745.14871 | 
| 76 | 1367.25 | 360.26 | 1006.986349 | 122497.8649 | 35158.86494 | 68752.13506 | 
| 77 | 1367.25 | 357.33 | 1009.923728 | 121487.9412 | 35516.19121 | 69762.05879 | 
| 78 | 1367.25 | 354.38 | 1012.869675 | 120475.0715 | 35870.57154 | 70774.92846 | 
| 79 | 1367.25 | 351.43 | 1015.824216 | 119459.2473 | 36221.99732 | 71790.75268 | 
| 80 | 1367.25 | 348.46 | 1018.787376 | 118440.4599 | 36570.45995 | 72809.54005 | 
| 81 | 1367.25 | 345.49 | 1021.759178 | 117418.7008 | 36915.95077 | 73831.29923 | 
| 82 | 1367.25 | 342.51 | 1024.73965 | 116393.9611 | 37258.46112 | 74856.03888 | 
| 83 | 1367.25 | 339.52 | 1027.728815 | 115366.2323 | 37597.9823 | 75883.7677 | 
| 84 | 1367.25 | 336.52 | 1030.7267 | 114335.5056 | 37934.5056 | 76914.4944 | 
| 85 | 1367.25 | 333.52 | 1033.73333 | 113301.7723 | 38268.02227 | 77948.22773 | 
| 86 | 1367.25 | 330.5 | 1036.74873 | 112265.0235 | 38598.52354 | 78984.97646 | 
| 87 | 1367.25 | 327.48 | 1039.772926 | 111225.2506 | 38926.00062 | 80024.74938 | 
| 88 | 1367.25 | 324.44 | 1042.805944 | 110182.4447 | 39250.44467 | 81067.55533 | 
| 89 | 1367.25 | 321.4 | 1045.847809 | 109136.5969 | 39571.84686 | 82113.40314 | 
| 90 | 1367.25 | 318.35 | 1048.898547 | 108087.6983 | 39890.19832 | 83162.30168 | 
| 91 | 1367.25 | 315.29 | 1051.958184 | 107035.7401 | 40205.49013 | 84214.25987 | 
| 92 | 1367.25 | 312.22 | 1055.026746 | 105980.7134 | 40517.71339 | 85269.28661 | 
| 93 | 1367.25 | 309.15 | 1058.104259 | 104922.6091 | 40826.85913 | 86327.39087 | 
| 94 | 1367.25 | 306.06 | 1061.190749 | 103861.4184 | 41132.91838 | 87388.58162 | 
| 95 | 1367.25 | 302.96 | 1064.286243 | 102797.1321 | 41435.88214 | 88452.86786 | 
| 96 | 1367.25 | 299.86 | 1067.390766 | 101729.7414 | 41735.74137 | 89520.25863 | 
| 97 | 1367.25 | 296.75 | 1070.504344 | 100659.237 | 42032.48703 | 90590.76297 | 
| 98 | 1367.25 | 293.62 | 1073.627006 | 99585.61002 | 42326.11002 | 91664.38998 | 
| 99 | 1367.25 | 290.49 | 1076.758776 | 98508.85124 | 42616.60124 | 92741.14876 | 
| 100 | 1367.25 | 287.35 | 1079.899681 | 97428.95156 | 42903.95156 | 93821.04844 | 
| 101 | 1367.25 | 284.2 | 1083.049748 | 96345.90182 | 43188.15182 | 94904.09818 | 
| 102 | 1367.25 | 281.04 | 1086.209004 | 95259.69281 | 43469.19281 | 95990.30719 | 
| 103 | 1367.25 | 277.87 | 1089.377476 | 94170.31534 | 43747.06534 | 97079.68466 | 
| 104 | 1367.25 | 274.69 | 1092.55519 | 93077.76014 | 44021.76014 | 98172.23986 | 
| 105 | 1367.25 | 271.51 | 1095.742174 | 91982.01797 | 44293.26797 | 99267.98203 | 
| 106 | 1367.25 | 268.31 | 1098.938454 | 90883.07952 | 44561.57952 | 100366.9205 | 
| 107 | 1367.25 | 265.11 | 1102.144057 | 89780.93546 | 44826.68546 | 101469.0645 | 
| 108 | 1367.25 | 261.89 | 1105.359011 | 88675.57645 | 45088.57645 | 102574.4236 | 
| 109 | 1367.25 | 258.67 | 1108.583343 | 87566.99311 | 45347.24311 | 103683.0069 | 
| 110 | 1367.25 | 255.43 | 1111.817081 | 86455.17602 | 45602.67602 | 104794.824 | 
| 111 | 1367.25 | 252.19 | 1115.060252 | 85340.11577 | 45854.86577 | 105909.8842 | 
| 112 | 1367.25 | 248.94 | 1118.312882 | 84221.80289 | 46103.80289 | 107028.1971 | 
| 113 | 1367.25 | 245.67 | 1121.575001 | 83100.22789 | 46349.47789 | 108149.7721 | 
| 114 | 1367.25 | 242.4 | 1124.846635 | 81975.38125 | 46591.88125 | 109274.6187 | 
| 115 | 1367.25 | 239.12 | 1128.127813 | 80847.25344 | 46831.00344 | 110402.7466 | 
| 116 | 1367.25 | 235.83 | 1131.418562 | 79715.83488 | 47066.83488 | 111534.1651 | 
| 117 | 1367.25 | 232.53 | 1134.71891 | 78581.11597 | 47299.36597 | 112668.884 | 
| 118 | 1367.25 | 229.22 | 1138.028885 | 77443.08709 | 47528.58709 | 113806.9129 | 
| 119 | 1367.25 | 225.9 | 1141.348515 | 76301.73857 | 47754.48857 | 114948.2614 | 
| 120 | 1367.25 | 222.57 | 1144.677829 | 75157.06074 | 47977.06074 | 116092.9393 | 
| 121 | 1367.25 | 219.23 | 1148.016854 | 74009.04389 | 48196.29389 | 117240.9561 | 
| 122 | 1367.25 | 215.88 | 1151.365619 | 72857.67827 | 48412.17827 | 118392.3217 | 
| 123 | 1367.25 | 212.53 | 1154.724152 | 71702.95412 | 48624.70412 | 119547.0459 | 
| 124 | 1367.25 | 209.16 | 1158.092483 | 70544.86163 | 48833.86163 | 120705.1384 | 
| 125 | 1367.25 | 205.78 | 1161.470639 | 69383.391 | 49039.641 | 121866.609 | 
| 126 | 1367.25 | 202.39 | 1164.858648 | 68218.53235 | 49242.03235 | 123031.4677 | 
| 127 | 1367.25 | 198.99 | 1168.256541 | 67050.27581 | 49441.02581 | 124199.7242 | 
| 128 | 1367.25 | 195.59 | 1171.664345 | 65878.61146 | 49636.61146 | 125371.3885 | 
| 129 | 1367.25 | 192.17 | 1175.08209 | 64703.52937 | 49828.77937 | 126546.4706 | 
| 130 | 1367.25 | 188.74 | 1178.509805 | 63525.01957 | 50017.51957 | 127724.9804 | 
| 131 | 1367.25 | 185.3 | 1181.947518 | 62343.07205 | 50202.82205 | 128906.928 | 
| 132 | 1367.25 | 181.85 | 1185.395259 | 61157.67679 | 50384.67679 | 130092.3232 | 
| 133 | 1367.25 | 178.4 | 1188.853057 | 59968.82373 | 50563.07373 | 131281.1763 | 
| 134 | 1367.25 | 174.93 | 1192.320941 | 58776.50279 | 50738.00279 | 132473.4972 | 
| 135 | 1367.25 | 171.45 | 1195.798941 | 57580.70385 | 50909.45385 | 133669.2962 | 
| 136 | 1367.25 | 167.96 | 1199.287087 | 56381.41676 | 51077.41676 | 134868.5832 | 
| 137 | 1367.25 | 164.46 | 1202.785407 | 55178.63135 | 51241.88135 | 136071.3686 | 
| 138 | 1367.25 | 160.96 | 1206.293932 | 53972.33742 | 51402.83742 | 137277.6626 | 
| 139 | 1367.25 | 157.44 | 1209.812692 | 52762.52473 | 51560.27473 | 138487.4753 | 
| 140 | 1367.25 | 153.91 | 1213.341715 | 51549.18302 | 51714.18302 | 139700.817 | 
| 141 | 1367.25 | 150.37 | 1216.881033 | 50332.30198 | 51864.55198 | 140917.698 | 
| 142 | 1367.25 | 146.82 | 1220.430675 | 49111.87131 | 52011.37131 | 142138.1287 | 
| 143 | 1367.25 | 143.26 | 1223.990671 | 47887.88064 | 52154.63064 | 143362.1194 | 
| 144 | 1367.25 | 139.69 | 1227.561052 | 46660.31958 | 52294.31958 | 144589.6804 | 
| 145 | 1367.25 | 136.11 | 1231.141848 | 45429.17774 | 52430.42774 | 145820.8223 | 
| 146 | 1367.25 | 132.52 | 1234.733089 | 44194.44465 | 52562.94465 | 147055.5554 | 
| 147 | 1367.25 | 128.92 | 1238.334805 | 42956.10984 | 52691.85984 | 148293.8902 | 
| 148 | 1367.25 | 125.3 | 1241.947028 | 41714.16281 | 52817.16281 | 149535.8372 | 
| 149 | 1367.25 | 121.68 | 1245.569787 | 40468.59303 | 52938.84303 | 150781.407 | 
| 150 | 1367.25 | 118.05 | 1249.203114 | 39219.38991 | 53056.88991 | 152030.6101 | 
| 151 | 1367.25 | 114.4 | 1252.84704 | 37966.54287 | 53171.29287 | 153283.4571 | 
| 152 | 1367.25 | 110.75 | 1256.501594 | 36710.04128 | 53282.04128 | 154539.9587 | 
| 153 | 1367.25 | 107.08 | 1260.16681 | 35449.87447 | 53389.12447 | 155800.1255 | 
| 154 | 1367.25 | 103.41 | 1263.842716 | 34186.03175 | 53492.53175 | 157063.9682 | 
| 155 | 1367.25 | 99.721 | 1267.529345 | 32918.50241 | 53592.25241 | 158331.4976 | 
| 156 | 1367.25 | 96.023 | 1271.226728 | 31647.27568 | 53688.27568 | 159602.7243 | 
| 157 | 1367.25 | 92.315 | 1274.934897 | 30372.34078 | 53780.59078 | 160877.6592 | 
| 158 | 1367.25 | 88.596 | 1278.653882 | 29093.6869 | 53869.1869 | 162156.3131 | 
| 159 | 1367.25 | 84.866 | 1282.383715 | 27811.30319 | 53954.05319 | 163438.6968 | 
| 160 | 1367.25 | 81.126 | 1286.124429 | 26525.17876 | 54035.17876 | 164724.8212 | 
| 161 | 1367.25 | 77.374 | 1289.876054 | 25235.3027 | 54112.5527 | 166014.6973 | 
| 162 | 1367.25 | 73.611 | 1293.638622 | 23941.66408 | 54186.16408 | 167308.3359 | 
| 163 | 1367.25 | 69.838 | 1297.412166 | 22644.25192 | 54256.00192 | 168605.7481 | 
| 164 | 1367.25 | 66.053 | 1301.196717 | 21343.0552 | 54322.0552 | 169906.9448 | 
| 165 | 1367.25 | 62.258 | 1304.992308 | 20038.06289 | 54384.31289 | 171211.9371 | 
| 166 | 1367.25 | 58.451 | 1308.798971 | 18729.26392 | 54442.76392 | 172520.7361 | 
| 167 | 1367.25 | 54.633 | 1312.616737 | 17416.64718 | 54497.39718 | 173833.3528 | 
| 168 | 1367.25 | 50.804 | 1316.44564 | 16100.20154 | 54548.20154 | 175149.7985 | 
| 169 | 1367.25 | 46.964 | 1320.285712 | 14779.91583 | 54595.16583 | 176470.0842 | 
| 170 | 1367.25 | 43.113 | 1324.136986 | 13455.77885 | 54638.27885 | 177794.2212 | 
| 171 | 1367.25 | 39.251 | 1327.999493 | 12127.77935 | 54677.52935 | 179122.2206 | 
| 172 | 1367.25 | 35.377 | 1331.873268 | 10795.90608 | 54712.90608 | 180454.0939 | 
| 173 | 1367.25 | 31.492 | 1335.758342 | 9460.147742 | 54744.39774 | 181789.8523 | 
| 174 | 1367.25 | 27.595 | 1339.654749 | 8120.492993 | 54771.99299 | 183129.507 | 
| 175 | 1367.25 | 23.687 | 1343.562522 | 6776.930471 | 54795.68047 | 184473.0695 | 
| 176 | 1367.25 | 19.768 | 1347.481694 | 5429.448778 | 54815.44878 | 185820.5512 | 
| 177 | 1367.25 | 15.838 | 1351.412298 | 4078.03648 | 54831.28648 | 187171.9635 | 
| 178 | 1367.25 | 11.896 | 1355.354368 | 2722.682112 | 54843.18211 | 188527.3179 | 
| 179 | 1367.25 | 7.9421 | 1359.307936 | 1363.374176 | 54851.12418 | 189886.6258 | 
| 180 | 1367.25 | 3.977 | 1363.273038 | 0.101138257 | 54855.10114 | 191249.8989 | 
b) From Amortization Table Sofie pays $838.164051 in first month of 2nd year that is month number 13 in the table.
c) From Amortization Table the remaining balance after 60th payment is $138262.9118 (month 60)
d) From Amortization Table in month 36
Total of interest payments of first 36 months = 18545.7727
Total of principal payments of first 36 months = 30675.22727
hence percentage of the total payments paid to interest for the first three years = (18545.7727/30675.22727)*100 = 60.46%