Avisitor is staying in a tent that is 11 kilometers west of the closest point on a shoreline to a coral reef. the coral reef is 3 kilometers due south of the shoreline. the visitor plans to travel from the tent to the coral reef by running and swimming. if the visitor runs at a rate of 7 kmph and swims at a rate of 2 kmph, how far should the visitor run to minimize the time it takes to reach the coral reef

Explanation:

Given:

distance of tent from the closest point on shore-line,

distance between shoreline point and coral reef,

As shown in the schematic by a green dashed line representing the shortest distance (say l) that the visitor runs towards the reef in order to swim a minimum distance which takes least time.

Now on reaching at the shore at this point the visitor will have to swim the least distance due east to reach coral reef.