Answer
$t = 2.4~hours$
Work Step by Step
We can find the total travel distance:
$d = (2)(1.3\times 10^9~km)$
$d = 2.6\times 10^{12}~m$
We can find the time it takes light to travel this distance:
$t = \frac{d}{c}$
$t = \frac{2.6\times 10^{12}~m}{3.0\times 10^8~m/s}$
$t = 8667~s$
$t = 2.4~hours$
