Answer:
Increase in monthly payment = 66
Explanation:
Given:
Amount = 100,000
Time, n = 25 years
Rate of 3% was used for the first 10 years.
Rate of 5% was used for the remaining 15 years.
Required:
Calculate the increase in the monthly payment.
To find the increase we are to subtract the original monthly payment from the new monthly payment.
First find the original monthly payment:
Original monthly payment [tex]= 100000* \frac{(1+0.03)^(^1^/^1^2^)-1)}{(1-1/(1+((1+0.03)^(^1^/^1^2^)-1))^(^1^2^*^2^5^))} = 472.108741438514[/tex]
Therefore, original monthly payment % 472.109
Now calculate the new monthly payment:
New monthly payment [tex]= 472.108741438514 / [((1+0.03)^(^1^/^1^2^)-1)* (1-1/(1+((1+0.03)^(^1^/^1^2^)-1)^(^1^2^*^1^5^))*((1+0.05)^(^1^/^1^2^)-1)/(1-1/(1+((1+0.05)^(^1^/^1^2^)-1))^(^1^2^*^1^5^))] = 538.1868715[/tex]
New monthly payment = 538.187
Increase in monthly payment = 538.187 - 472.109 = 66.078
Increase in monthly payment ≈ 66