The time formula for simple interest is:
[tex]t=\frac{I}{Ci}[/tex]Where I is the interest, C is the capital and i is the rate
In this case, we have:
I= 867
i=6.8%
C=17000
Replace and solve:
[tex]t=\frac{867}{17000*0.068}[/tex][tex]t=0.75\text{ years}[/tex]The time is 0.75 years because the rate is in years.
Convert years to months:
[tex]0.75years*\frac{12months}{1years}=9\text{ months}[/tex]