Answer:
6.3 years
Step-by-step explanation:
The growth factor each year is 1+19% = 1.19. You want to find the number of years (t) that result in a multiplier of 3 for the account value:
3 = 1.19^t
Taking logarithms, you get ...
log(3) = t·log(1.19)
log(3)/log(1.19) = t ≈ 6.32
It will take a little more than 6 years for Casey/Brad's investment to triple in value.
