The correct option is D 26
While travelling to 10 miles East and then 24 miles South the boat is moving on the path to form a right angled triangle.
The distance c then would be the hypotenuses of the triangle, which can be calculated using Pythagorean Theorem which is a2+b2=c2.
As we have the measurements of the two sides making the right angle:
⇒102+242=c2
⇒100+576= c2
⇒c2 =676
⇒c =26 miles
Hence, the option C is the right answer.
Ans: C