Question 1205494
<font color=black size=3>
300,000 = 3*10^5
6 billion = 6*10^9


1 hour = 60*60 = 3600 seconds
100 hours = 100*3600 = 360,000 seconds
360,000 = 3.6*10^5


Determine the speed of the spaceship
distance = rate*time
rate = distance/time
rate = (6*10^9 km)/(3.6*10^5 seconds)
rate = (6/3.6)*((10^9)/(10^5)) km per second
rate = (60/36)*10^4 km per second
rate = (5/3)*10^4 km per second


Divide this over the speed of light to wrap things up
( spaceship's speed )/( speed of light )
( (5/3)*10^4 )/( 3*10^5 )
( (5/3)*10^4 )/( 3*10*10^4 )
( (5/3)*10^4 )/( 30*10^4 )
( (5/3)/30 )*((10^4)/(10^4))
(5/3)/30
(5/3)*(1/30)
5/90
<font color=red>1/18</font> is the final answer.


---------------------------------------------------------


Another approach


Let's see how long it takes a light beam to go from Earth to Pluto
distance = rate*time
time = distance/rate
time = (6*10^9 km)/(3*10^5 km per sec)
time = (6/3)*((10^9)/(10^5)) sec
time = 2*10^4 sec
time = 20,000 sec


Divide this over 360,000 seconds (the time it takes the spaceship to reach Pluto) and you should get the fraction <font color=red>1/18</font>
It represents the idea that the light beam can travel to Pluto 18 times in the same timespan the spaceship travels.
In other words, the light beam travels 18/2 = 9 round trips from Earth to Pluto, and back. In these 9 round trips of the light beam, the spaceship will arrive at Pluto.


---------------------------------------------------------


Answer:  <font color=red>1/18</font>
</font>