What is the total magnification of a refracting telescope having an objective and eyepiece lens of focal lengths 30.0 cm and 0.40 cm respectively?

The total magnification of a refracting telescope is -75

Explanation:

f₀ = 30 cm

= 0.40 cm

Magnification in telescope => m = - f₀ /  

                                                    m = - 30 / 0.040

                                                    m = -75

Magnification in telescope = -75

The negative sign shows the image is inverted

c)as speed changes, wavelength and frequency change.

everything changes!

i think the answer would be b