For future reference
a) The time that has passed on the rocketship before reaching the station is 40 minutes. We know that
b) We want to know the value of x, the distance from the station to the Earth. If we stay in the Earth's frame, we don't need relativity any more:
c) At 3:24 (Earth time) the rocketship is sending a radio signal to the Earth from a position of . Radio signals are a form of light emission, and thus travel at a speed of c in any reference frame, so the amount of time it takes for the light signal to get to the Earth from this position is
So the clock reading on Earth when the signal reaches Earth is 3:43:12.