Question

Consider a 30-year, $300,000 mortgage with monthly payments and a nominal rate (monthly compounding) of 6.50%. What portion of the first 35 payments goes toward paying principal?

the answer is 15.70% but I don't know how to get the answer with a HP 10bII+ financial calculator, so if possible brake down the steps for me

Answer 1

EMI = Loan / PVAF (r%, n)

= $ 300,000 / PVAF(0.5417%, 360 )

= $ 300,000 / 158.2108

= $ 1896.20

Loan AMortization:

Month	Opening Bal	Instalment	Int	Principal Repay	Clsoing Bal
1	$ 3,00,000.00	$ 1,896.20	$ 1,625.00	$      271.20	$ 2,99,728.80
2	$ 2,99,728.80	$ 1,896.20	$ 1,623.53	$      272.67	$ 2,99,456.12
3	$ 2,99,456.12	$ 1,896.20	$ 1,622.05	$      274.15	$ 2,99,181.97
4	$ 2,99,181.97	$ 1,896.20	$ 1,620.57	$      275.64	$ 2,98,906.34
5	$ 2,98,906.34	$ 1,896.20	$ 1,619.08	$      277.13	$ 2,98,629.21
6	$ 2,98,629.21	$ 1,896.20	$ 1,617.57	$      278.63	$ 2,98,350.58
7	$ 2,98,350.58	$ 1,896.20	$ 1,616.07	$      280.14	$ 2,98,070.44
8	$ 2,98,070.44	$ 1,896.20	$ 1,614.55	$      281.66	$ 2,97,788.79
9	$ 2,97,788.79	$ 1,896.20	$ 1,613.02	$      283.18	$ 2,97,505.60
10	$ 2,97,505.60	$ 1,896.20	$ 1,611.49	$      284.72	$ 2,97,220.89
11	$ 2,97,220.89	$ 1,896.20	$ 1,609.95	$      286.26	$ 2,96,934.63
12	$ 2,96,934.63	$ 1,896.20	$ 1,608.40	$      287.81	$ 2,96,646.82
13	$ 2,96,646.82	$ 1,896.20	$ 1,606.84	$      289.37	$ 2,96,357.46
14	$ 2,96,357.46	$ 1,896.20	$ 1,605.27	$      290.93	$ 2,96,066.52
15	$ 2,96,066.52	$ 1,896.20	$ 1,603.69	$      292.51	$ 2,95,774.01
16	$ 2,95,774.01	$ 1,896.20	$ 1,602.11	$      294.09	$ 2,95,479.92
17	$ 2,95,479.92	$ 1,896.20	$ 1,600.52	$      295.69	$ 2,95,184.23
18	$ 2,95,184.23	$ 1,896.20	$ 1,598.91	$      297.29	$ 2,94,886.94
19	$ 2,94,886.94	$ 1,896.20	$ 1,597.30	$      298.90	$ 2,94,588.04
20	$ 2,94,588.04	$ 1,896.20	$ 1,595.69	$      300.52	$ 2,94,287.52
21	$ 2,94,287.52	$ 1,896.20	$ 1,594.06	$      302.15	$ 2,93,985.37
22	$ 2,93,985.37	$ 1,896.20	$ 1,592.42	$      303.78	$ 2,93,681.59
23	$ 2,93,681.59	$ 1,896.20	$ 1,590.78	$      305.43	$ 2,93,376.16
24	$ 2,93,376.16	$ 1,896.20	$ 1,589.12	$      307.08	$ 2,93,069.08
25	$ 2,93,069.08	$ 1,896.20	$ 1,587.46	$      308.75	$ 2,92,760.33
26	$ 2,92,760.33	$ 1,896.20	$ 1,585.79	$      310.42	$ 2,92,449.91
27	$ 2,92,449.91	$ 1,896.20	$ 1,584.10	$      312.10	$ 2,92,137.81
28	$ 2,92,137.81	$ 1,896.20	$ 1,582.41	$      313.79	$ 2,91,824.02
29	$ 2,91,824.02	$ 1,896.20	$ 1,580.71	$      315.49	$ 2,91,508.53
30	$ 2,91,508.53	$ 1,896.20	$ 1,579.00	$      317.20	$ 2,91,191.33
31	$ 2,91,191.33	$ 1,896.20	$ 1,577.29	$      318.92	$ 2,90,872.41
32	$ 2,90,872.41	$ 1,896.20	$ 1,575.56	$      320.65	$ 2,90,551.77
33	$ 2,90,551.77	$ 1,896.20	$ 1,573.82	$      322.38	$ 2,90,229.39
34	$ 2,90,229.39	$ 1,896.20	$ 1,572.08	$      324.13	$ 2,89,905.26
35	$ 2,89,905.26	$ 1,896.20	$ 1,570.32	$      325.88	$ 2,89,579.37
	Amount towards Principal	$ 10,420.63
	No .of Instalments	35
	Instalment Amount	$   1,896.20
	Amount Paid	$ 66,367.14
	% towards to Principal	15.70%