Question

Given that an astronomical unit is 1.5e8km and a light year about 10^3 km, how many AU are in a light year?

Answer 1

Answer:

There are approximately 66666 astronimic units in a light year

Explanation:

This is a simple exercise of ratios.

Since the astronomic unit is 1.5e8 km and the light year is 10^13 km (the question had an error) we can write:

$1 = \frac{x * AU}{1 LY}$

So:

$x = \frac{1 LY}{1 AU} = \frac{1e13 km}{1.5e8 km} = 666666$