At Dec. 31, 2013 bonds payable of $100,070,000 are outstanding. The bonds pay 12% interest every September 30 and mature in installments of $28,731,000 every September 30, beginning September 30, 2014.

Maturity of Bonds Payable: $28,731,000

Bonds Payable: $71,339,000
100,070,000 - 28,731,000 = 71,339,000

Interest Payable:??
$28,731,000*.12= $3,447,720

Not sure how to go about finding interest payable. Please Help.

Or does this look correct for interest payable?

$100,070,000 * 0.12 * (3/12) = $3,002,100

If so, please explain to me why to use $100,070,000 instead of the maturity value ($28,731,000)