A 55-kg woman contestant on a reality television show is at rest at the south end of a horizontal 148-kg raft that is floating in crocodile-infested waters. She and the raft are initially at rest. She needs to jump from the raft to a platform that is several meters off the north end of the raft. She takes a running start. When she reaches the north end of the raft she is running at 4.4 m/s relative to the raft. At that instant, what is her velocity relative to the water?

I did this....
m(w)*v(w) + m(r)*v(r) = 0
v(r) = -1.64

v(w) + v(r) = v(w)(relative to water) = 2.76 = incorrect?