Answer:
3.6miles
Step-by-step explanation:
Given:
distance of tent from the closest point on shore-line, d=3miles.
distance between shoreline point and coral reef, x=2miles
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.