Two boats are heading towards each other at constant speeds of 5 miles/hr and 25 miles/hr respectively. They begin at a distance 20 miles from each other. How far are they (in miles) one minute before they collide ?	Choose the correct choice from the following options:  A) 1 / 12  B) 5 / 12  C) 1 / 6  D) 1 / 2  E) 1 / 5

Rationale: "the question asks : how far apart will they be 1 minute = 1 / 60 hours before they collide ? since the combined rate of the boats is 5 + 25 = 30 mph then 1 / 60 hours before they collide they ' ll be rate * time = distance - - > 30 * 1 / 60 = 1 / 2 miles apart . answer : d ."
Answer: D