A man on a cliff observes a boat at an angle of depression of 30^{0} which is approaching the shore to the point immediatly beneath the observer with a uniform speed. Six minutes later,the angle of depression of the boat is found to be 60^{0}.Find the time taken by the boat to reach the shore.

We have-

Let the uniform velocity be v and the the distance to be travelled by the boat to reach the soar be x.

So,

.......(1)

Similarly,

........(2)

Divide equation(1) by (2) to get,

**Hence the time taken to reach the soar is 3 minutes**

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