Question

A 2-inch, f/4 reflector has a focal length of:

2 inches
4 inches
6 inches
8 inches

Answer 1

I think it might be 8 inches

Step-by-step explanation:

My reasoning for this answer is that when you want the focal length of a telescope, you multiply the number behind the "f/?" so in other words, it would be

2 * 4 = 8

Answer 2

The focal length would be four inches.