Respuesta :

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.