Answer
$\$15$
Work Step by Step
The simple interest formula where $r$ is the rate of interest, $t$ is the time in years is, $P$ is the principal, $A$ is the amount you get back after $t$ years:
$A=P(1+rt). $
Here we have:
$P=\$500$
$r=6\%=0.06$.
$t=0.5$.
Substitute these values into the formula above to obtain: $A=500(1+0.5\cdot0.06)=500(1+0.03)=500\cdot1.03=\$515$.
Therefore the interest is: $515-500=\$15$
