Please help me solve the following using a financial calculator:

1)

Consider a $100,000, 30-year, 5.4% mortgage with monthly payments. What portion of the payments during the first 25 months goes toward principal?

20.17%

21.25%

22.78%

22.41%

20.98%

2)

Consider a $100,000, 30-year, 6.9% mortgage with monthly payments. What portion of the payments during the first 31 months goes toward interest?

82.91%

93.71%

86.15%

80.72%

90.37%