Question

How to find time if principal rate and interest are given

Answer 1

If simple interest is given,

Then you can use the formula

Si = p*r*t/100
Here si is simple interest
P is Principal
R is rate
T is time

To calculate time, just cross multiply both sides,

t = (si * 100)/ p*r


If compound interest is given, you can use the formula,

Ci = p ( 1+ r/100)^n

Here ci is the compound interest
P is Principal
R is rate
N is the number of years

To calculate n, you need to take log on both sides,

Log ci = p*n*log (1+r/100)

n = [log (ci - 1 - r/100)] / p