compound interest formula

Question

F=4*P

 

P=P

 

R=10%

 

f=365

 

Using compound interest formula F(t)=P(1+r/f)^f*t

 

 

Solve for t in terms of F,P,r,and f. Calculate how many years it will take for invested amount to quadruple in value if annual interest rate is 10% compounded daily?

Answer 1

F = P(1 + (r / f))^ft

 

 

Substitute the given variables into the formula.

 

4P = P(1 + (0.10 / 365))^365t

 

 

Divide both sides of equation by P.

 

4 = (1 + (0.10 / 365))^365t

 

 

Log both sides of equation and bring the exponent down as the coefficient of the Log.  We use logarithms when solving for an exponential value.

 

Log(4) = 365t Log(1 + (0.10 / 365))

 

 

Divide both sides of equation by 365Log(1 + (0.10 / 365)).

 

t = Log(4) / [365Log(1 + (0.10 / 365))]