Final answer:
The cruise ship is approximately 40.3 miles from where it started.
Step-by-step explanation:
To find the distance the cruise ship is from where it started, we can use the Pythagorean theorem. The ship traveled 20 miles due north and 35 miles due west, forming a right triangle. The distance from the starting point is the hypotenuse of the triangle. Using the theorem, we can calculate the distance as:
d = sqrt(20^2 + 35^2) = sqrt(400 + 1225) = sqrt(1625) = 40.3 miles
Therefore, the cruise ship is approximately 40.3 miles from where it started.