Answer:- 0.134 seconds
Solution:- The speed is given as
and the circumference is 24900 miles which is same as the distance light have to covered. It asks to calculate the time required to cover this distance by the light.
We need to do unit conversion from miles to meter as the speed is given in meter per second.
1 mile = 1609.34 meter
So, 
= 40072566 meters
Know that, 
It's rearranged to time as, 
Let's plug in the values in it:

= 0.134 seconds
So, the light would take 0.134 seconds to travel the mentioned speed. The answer without the unit is 0.134.
Answer: 67.23 L
Explanation:
According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number
of particles.
To calculate the number of moles, we use the equation:
Putting in the values we get:
1 mole of methane occupies = 22.4 L
Thus 3 moles of methane occupy = 
Thus volume of 48 grams of methane gas is 67.23 L
5604000gallon =21239160 liters