Question

Candice deposited $3,587.39 into a savings account with an interest rate of 4.2% compounded twice a year. About how long will it take for the account to be worth $5,000?

Answer 1

Time taken for the amount deposited to grow to $5000 will be found as follows:
A=P(1+r/100*n)^nt
where:
A=amount
P=principle
r=rate
n=number of terms
t=time
thus plugging in our values we have:
5000=3587.39=(1+4.2/200)^2t
solving for t we have:
1.393771=1.021^2t
2t=ln1.393771/ln1.021
2t=16.111
t=8.055685 years~8 years