Question

A $4,000.00 principal earns 5% interest, compounded annually. After 4 years, what is the balance in the account?

Answer 1

First question:
interest rate is 5% annually. After 4 years relative value of interest will be 1.05^4
Now we multiply that with starting funds and get
4000* 1.05^4 = 4862.03

Second question:
Because interest is 8% semiannually that means that after 35 years relative value of interest will be   1.04^(35*2)
6000*1.04^70 = 93,429.71

Third question:
after first year tractor's value will be 0.86*15450. After 3 years its value will be:
(0.86)^3*15,450 = 9,827.07