Answer:
1.35208 m/s
Step-by-step explanation:
Speed of the boat = 0.75 m/s
Distance between the shores = 100 m
Time = Distance / Speed

Time taken by the boat to get across is 133.33 seconds
Point C is 150 m from B
Speed = Distance / Time

Velocity of the water is 1.125 m/s
From Pythagoras theorem

So, the man's velocity relative to the shore is 1.35208 m/s