Just follow this formula:
I=PRT (I-interest, P-principal, R-rate, T=time)
I=Total amount-principal
Answer:
I=$249,750 - $225,000
I=$24,750
I=PRT
$24, 750= $225, 000 x r x 1
$24, 750= $225, 000 x r
$24, 750 / $225, 000 =r
0.11 = r
(Change to percent)
11% = r
Check:
$24, 750= $225, 000 x 11% x 1
$24, 750= $225, 000 x.11
$24, 750=$24, 750, CORRECT!!!
Therefore, the interest rate is 11 % per annum. (or 11% per 1 year)