Answer
$5.0\times 10^{2}$ seconds
Work Step by Step
Given that the speed of light is 186,000 miles per second,
the time it takes light to cover 93,000,000 miles is
$\displaystyle \frac{93,000,000}{186,000}=500$ seconds
To write 500 in scientific notation,
$500=5\times 100= 5.0\times 10^{2}$ seconds