Answer:
The resultant velocity is 
Explanation:
Apply the law of conservation of momentum

Where
is the mass of the Luxury Liner = 40,000 ton
is the velocity of Luxury Liner = 20 knots due west
mass of freighter = 60,000
is the velocity of freighter = 10 knots due north
Apply the law of conservation of momentum toward the the west direction

So the equation would be

Substituting values

Where
the final velocity due west
Making
the subject


Apply the law of conservation of momentum toward the the north direction

So the equation would be

Where
the final velocity due north
Making
the subject


The resultant velocity is


