<PRE><B>Question 1088272</B>
A = Accrued amount (principal + interest, in this case 25000
P = Principal (initial amount, in this case 10000)
r = rate 0.072
n = number of compounding periods (12)
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In the compound interest formula, time is an exponent:
A = P(1+(r/n))^(nt)
In order to solve for an exponent we have to use logarithms.
Take the formula above, do a little algebra on it, and you get:
t = ln(A/P)/n[ln(1+r/n)] = [ln(A)-ln(P)]/n[ln(1+r/n)]
Now just plug in your numbers:
t = [ln(25000/10000)]/[12(ln(1+(0.072/12)))]
t = (ln25000-ln10000)/12(ln(1+0.006))
t = 10.12-9.21/(0.072)
t = 12.64 years
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