Uninhibited Growth Model. This is an example problem from the book and need help figuring it out?

a) If $3500 is invested in an account that pays 5% interest compounded continuously, how long will it take to grow to $7000.

b) How much money will the account be worth in 20 years.

2 answers

a. P = Po*e^rt.
P = 3500*e^rt = 7,000,
e^rt = 2.0,
rt*Lne = Ln 2,
r*t = 0.693,
0.05t = 0.693,
t = 13.9 Years.

b. P = Po*e^rt.
Po = $3500
r*t = 0.05 * 20,
P = ?
I understand part A perfectly well now. But I am confused with part B once I get $3500^0.05*20 would P just be $3500 or 1 as the answer?