Please I need help.

The Moon orbits the Earth at an average distance of 3.84 x 10 km with an orbital period of 0.07481 yr. Pluto, which is one of the satellites of the Sun orbits its parent at an average distance o 5.90 x 10 km with an orbital period of 248.3 yr. (a) Use the above information to find the orbital speeds of the Moon around the Earth and of Pluto around the Sun. VMoon = m/s Vpiuto = m/s (b) What is the expression for the mass M of the parent in terms of the orbital speed v of the satellite, the orbital radius R of the satellite and the gravitational constant G? (Do not substitute numerical values; use variables only.) M= (c) Now use your answers from parts (a) and (b) to find the ratio of the mass of the Sun to that of the Earth. M s