Answer:
9.694 years
Step-by-step explanation:
Let the investment is $P.
So, we are asked to determine the time it will grow to triple with the compound interest rate of 12%.
Let the time is y years.
So, from the formula of compound interest we can write
[tex]3P = P(1 + \frac{12}{100} )^{y}[/tex]
⇒ [tex](1 + \frac{12}{100} )^{y} = 3[/tex]
⇒ [tex](1.12)^{y} = 3[/tex]
Now, taking log both sides we get,
y log 1.12 = log 3 {Since, [tex]\log a^{b} = b \log a[/tex] }
⇒ 0.04922y = 0.477712
⇒ y = 9.694 years (Answer)