Question

compute the value of the magnifying power of a 150-inch fl8 telescope with an eyepiece of one-half-inch focal length

Answer 1

150 inches at f/8 gives a focal length of 1200 inches.

Divide 1200 inches by 1/2 inch eye piece to get the magnification of 2400x.

Answer 2

assume fl8 is f/8

150" at f/8 means the focal length = 150*8 = 1200 inches

divide by eyepiece of 1/2", the magnifying power = 1200/(1/2) = 2400X