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CGP EDU Academic Team
Published on: August 14, 2026
A harbour lies in the direction 60° south-west from a fort and at a distance of 30 km from it. A ship sets out from the harbour at noon and sails due east at 10 km/hour, then the time (in hours) in the evening at which the ship will be 70 km from the fort is
Text Solution
Verified by ExpertsThe correct answer is:
CHECK THE SOLUTION.
8
Let A be the position of the harbour and O be of the fort. OA = 30, OB = 70. Let AB = x.
Applying cosine formula in 
OAB, we get
x=80
Speed of ship =10 km/hr
Time =8 hrs
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