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Elevation above sea level = 2x+50
rock climbers minute of climbing = x
2x + x + 50
3x + 50
Answer:
Correct!
Step-by-step explanation:
You did it the correct mathematical way, where you divide 4 by 30. Some people get confused and multiply 30 and 4, so good job!
Part A: monthly payment
Initial loan after downpayment,
P = 320000-20000= 300,000
Interest rate per month,
i = 0.06/12= 0.005
Number of periods,
n = 30*12= 360
Monthly payment,
A = P*(i*(1+i)^n)/((1+i)^n-1)
= 300000(0.005(1.005)^360)/(1.005^360-1)
= 1798.65
Part B: Equities
Equity after y years
E(y) = what they have paid after deduction of interest
= Future value of monthly payments - cumulated interest of net loan
= A((1+i)^y-1)/i - P((1+i)^y-1)
= 1798.65(1.005^y-1)/.005 - 300000(1.005^y-1)
= (1798.65/.005-300000)(1.005^y-1)
Equity E
for y = 5 years = 60 months
E(60) = (1798.65/.005-300000)(1.005^60-1) = 18846.17
for y = 10 years = 120 months
E(120) = (1798.65/.005-300000)(1.005^120-1) = 45036.91
y = 20 years = 240 months
E(240) = (1798.65/.005-300000)(1.005^240-1) = 132016.53
Check: equity after 30 years
y = 30 years = 360 months
E(360) = (1798.65/.005-300000)(1.005^360-1) = 300000.00 .... correct.
