The simple interest formula is give by
[tex]I=P\times r\times t[/tex]where I is the interest earned after t years and r is the rate of interest. In our case, P= $6500, r= 0.05 and t=3.5 years.
By substituting these values into the simple interest formula, we get
[tex]I=6500\times0.05\times3.5[/tex]which gives
[tex]I=1137.5[/tex]that is, the interest will be $1,137.5