Final answer:
Pluto receives roughly 1/1521 of the sunlight intensity that reaches Earth, calculated using the inverse square law and Pluto's average distance from the Sun, which is 39 times that of Earth.
Step-by-step explanation:
The intensity of sunlight that reaches a planet decreases with the square of the distance from the Sun. Given that Pluto is on average 39 times as far from the Sun as Earth is, we can use the inverse square law to calculate the sunlight intensity ratio. By squaring the factor by which Pluto's distance exceeds Earth's (39^2), we find that Pluto receives 1/(39^2) or approximately 1/1521 of the sunlight intensity that Earth receives.