The average distance from the sun to pluto is approximately 6.10 time 10^9 km. how long does it take light from the sun (384,000 km/s) to reach pluto?

From the information as given in the question, the transit time
for light from the sun would be

       (6.1 x 10⁹ km) / (3.84 x 10³ km/sec) = 15,885 seconds (rounded).
                                                                       (4.4 hours) .


-- A better figure for Pluto's average distance from the sun is  5.874 x 10⁹ km.

-- " 384,000 km/sec " is about 28% too high for the speed of light.
    A much better figure is  300,000 km/sec.

Using these numbers, the transit time is

           (5.874 x 10⁹ km) / (3 x 10⁵ km/sec)  =  19,580 seconds
                                                                             (5.4 hours)