> Simple interest problem?

Simple interest problem?

Posted at: 2014-12-05 
$250 in 7 yrs equals 35.71 per year. That's 1.786%, not 18%.

A 7-year bond costs $2,000 and will pay a total of $250 interest over its lifetime. What is its annual interest rate r?

I got 18%

It's wrong

Can someone help me out please, thanks!!

If possible write me the answer rounded to 3 decimal places