We've got m/s, which is value of distance ÷ time
(distance/time)
3 x 10^8 is:
300,000,000m/s
1km = 1000m
1hr = 3600secs
So, divide 300,000,000m by 1000 to get in km & you get:
300,000km
Now divide this value by 3600 seconds to get it in km/hr
300,000km/3600 = 83.33333333
Thus, answer is 83.3km/h
Or
8.33 x 10^1 km/h (in standard form)
(doing 83.3 recurring multipled by 1000 & 3600 gets you back to original answer. So, 83.33333...x1000x3600= 300,000,000)
Hope this helps!