What is the speed of light?

Dear Student,
The speed of light in a vacuum is 186,282 miles per second (299,792, 458 m per second).
Also in other systems of measurement:
Miles per hour: 671000000
Kilometres per hour: 1080000000
Parsecs per hour: 0.307
But, to use in questions, it can be approximately taken as $3\times {10}^8$ metres per second.
Regards