Answer:
A)  14.2 years   B)  23.84 years
Step-by-step explanation:
 A = P( 1 + r/n)^nt    P = 2500  A = 2P = 5000  r = 0.05  n = 1  FInd t
                          A = 8000   Find t
I used a financial calculator to find this
t = 14.2 years
Â
A = P( 1 + r)^t
A/P = ( 1 + r)^t
5000/2500 = (1.05)^t
 2 = 1.05^t     I don't remember how to solve this for t
8000/2500 = 1.05^t     t = 23.84    according to the fin calculator