(Please help) Math
posted by Hannah on .
1) initial investment = $600
annual % rate = ?
time to double = ?
amount after 10 years = $19,205.00
19,205 = 600e^(10r)
I do not know how to solve for r of find the time to double.

That looks like a misprint, but if the investment really increased that fast,
19,205 = 600 (1 + r)^10
10 ln (1+r) = ln (19,205/600) = ln 32.0
= 3.4657
ln (1+r) = 0.34657
1+r = 1.414
r = 41.4%
The time to double is 2.0 years