pre calc
posted by Anthony .
How long would it take from 3000 to get to 8000 at 8% interest at compounded quarterly?

3000(1.02)^n = 8000 , where n is the number of quarter years
1.02^n = 8/3
take log of both sides
log 1.02^n = log (8/3)
using log rules ...
n log1.02 = log8  log3
n = (log8  log3)/log1.02 = 49.53
it will take appr 49.53 quarter years or
12.4 years