A boat leaves a dock at 1:00 PM and travels due south at a s…
A boat leaves a dock at 1:00 PM and travels due south at a speed of 20 km/h. Another boat has been heading due east at 10 km/h and reaches the same dock at 3:00 PM. How many minutes after 1:00 PM were the two boats closest together? (Round your answer to the nearest minute.)