An observer in frame S' is moving to the right (+ x-direction) at speed u = 0.600c

Question:

An observer in frame S' is moving to the right (+ x-direction) at speed u = 0.600c away from a stationary observer in frame S. The observer in S' measures the speed v' of a particle moving to the right away from her. What speed v does the observer in S measure for the particle if
(a) v' = 0.400c;
(b) v' = 0.900c;
(c) v' = 0.990e?