Answer:
option (b)
Step-by-step explanation:
Mass of moon = m
Mass of earth = 81.25 x mass of moon = 81.25 m
Radius of moon = r
radius of earth = 3.668 x radius of moon = 3.668 r
Frequency on earth = 2 Hz
Let the frequency on moon is f.
The formula for the frequency is given by

The value of acceleration due to gravity on earth is g.
ge = G Me / Re^2
ge = G x 81.25 m / (3.668 r)^2
ge = 6.039 x G m / r^2 = 6.039 x gm
ge / gm = 6.039
Now use the formula for frequency



fm = 0.814 Hz