Please show your work so I can understand the process

A rocket flies at constant speed to a newly discovered planet beyond Pluto. The trip takes 40 hours in the Earth's frame of reference. However, the trip only takes 30 hours according to clocks on board the rocket.

a) What is the velocity of the rocket?

b) What is the distance of the planet from earth measured in light-hours? (1 light-hour is the distance light can travel on 1 hour.)