Çözüldü Compound Interest Computation - Logarithm

A slightly harder version of a problem from the Washington State University.

How many years does it take to triple an investment compounded annually at an interest rate of 7.5%?

Investment: Capital (C)
Time: t years
3C = C·(1 + 7.5 / 100)^t
3 = (1 + 7.5 / 100)^t
log(3) = t·log(107.5 / 100)
log(3) = t·[ log(1.075) ]
t = log(3) / log(1.075)
t ≈ 15.2 years.

Original Question and Solution:

https://i.ibb.co/VVcRsFh/Compound-Interest.png
http://www.math.wsu.edu/faculty/bkrishna/FilesMath201/F08/Exams/Sol_Sample_Test2.pdf
(Last Problem)

Notes:
1. No change depending on the logarithm base
2. Some calculators are allowed on SAT.