Calculating Angular Size of Moon with Telescope

[A B C]

Homework Statement

The moon is observed using a telescope that has an objective lens with a focal length of 3.0 m and an eyepiece with a focal length of 7.5 cm. What is the angular diameter of the moon if the earth-moon distance is 3.85 × 108 m and the diameter of the moon is 3.48 × 106 m?
(a) 0.36 rad (c) 9.0 rad (e) 40 rad
(b) 4.7 rad (d) 22 rad

Homework Equations

0 = ho / do

The Attempt at a Solution

0 : the angular size.
ho: the high of the object
do: the distance of the object

 

[collinsmark]

Hello A B C,

What do you think?

 

[A B C]

Hello A B C,

What do you think?

I think it's 0.36 rad, but I'm not sure

 

[collinsmark]

I think it's 0.36 rad, but I'm not sure

Fair enough. But if you want us to confirm, you'll have to show us your work.

Let me ask you,
(i) What's the angular diameter of the moon without the telescope?
(ii) What's the telescope's magnification?
(iii) Are you more sure of your answer after finding (i) and (ii)?