A pursuit spacecraft from the planet Zirkon is attempting to catch up with a Trade Federation cruiser. As measured by an observer on Zirkon, the cruiser is traveling away from the planet with a speed of 0.400 c The pursuit ship is traveling at a speed of 0.740 c relative to Zirkon, in the same direction as the cruiser. What is the speed of the cruiser relative to the pursuit ship?
Express your answer as a multiple of speed of light cc.