Answer:
7 years
Step-by-step explanation:
Given :
The Simple Interest earned, I = $ 6720
Rate of interest, r = 8% per annum
Principal amount, P = $12,000
We known that :
[tex]$I = \frac{P \times T \times r}{100}$[/tex]
Here t is the number of years of investment.
Therefore,
[tex]$t= \frac{I \times 100}{p \times r}$[/tex]
[tex]$t= \frac{6720 \times 100}{12000 \times 8}$[/tex]
t = 7
So, the sum was invested for 7 years.