Determines in years (with an approximation of 2 decimals the time T needed to triple an initial amount Co placed in a banking institution that models the investment with the equation?

Determines in years (with an approximation of 2 decimals the time T needed to triple an initial amount Co placed in a banking institution that models the investment with the equation.enter image source here

answers:
A) 5.33
B) 53.32
C) 8.45
D)84.51

1 Answer
Dec 6, 2017

#8.45#

Explanation:

Using an arbitrary value for the initial amount, say $10.

Triple this is $30. So:

#30=10e^(0.13t)#

Dividing by 10:

#3=e^(0.13t)#

Taking natural logs of both sides:

#ln3=0.13tcolor(white)(88)# ( #lne=1#, log of base is always 1 )

Divide by #0.13#

#ln3/0.13=t=>t=8.450863759=8.45# ( 2 .d.p.)