F(t) = 1000 * 1.,08 * t
Initiaton deposition 1000
interest annually
t = years
How long does it take to double the amount , 1000 * 2= 2000
2000 = 1000 * 1,08^t
2000 / 1000 = 1,08 ^t
2 = 1,08^t
log 2 = log 1,08 ^t
log 2 = t * log 1,08
log 2 / log 1,08 = t
t = 9 years
