No particle can travel faster than the speed of light and i dont think u can use something like that just adding the relative velocities.

 i think the answer would not be as given above.....that's relative velocitybut yet u cannot attain velocity more than that of light........actually the thing is that time adjusts itself in such a way that the relative velocity never exceeds more than that of light....for example....if we r on a vehical moving with a speed 99.99% that of light.....then if we start running inside the vehical in the same direction as the space ship.....time wud slow itself for us so that our combined velocity does not exceeds that of light.