1)Light travels at the speed of 3,00,000 km in one second ,if it has
already travelled 1,05,342 km, how much more distance is left for the
ray of light to travel?
If you are talking about how much distance it has to travel in 1 second then you can simply subtract 1,05,342 from 3,00,000. This process gives total of 1,94,658km remaining for it to travel.