The average distance from the sun to the Earth
is about 152 million kilometers.
That's (1.52 x 10⁸ km).
Time to cover the distance = (distance) / (speed)
Time = (1.52 x 10⁸ km) / (3 x 10⁵ km/s)
= (506 and 2/3) seconds.
That's 8 minutes 27 seconds .
The popular number is "about 8 minutes".
