Answer
$404
Work Step by Step
We can calculate simple interest on a loan by using the formula $I=prt$ (where I is the interest, p is the principal, r is the rate of interest, and t is the amount of time - expressed in years).
$t=\frac{1}{2}$, because 6 months equals .5 years
$I=prt$
$I=400\times.02\times\frac{1}{2}=4$ dollars
Finally, we can find the amount due by adding the interest to the original principal.
$400+4=404$ dollars
