A boat heads south at 1,200 mph while a steamer heads east at 500 mph. If they started from the same dock and at the same time, when will the distance between them be 1,300 mi?

If they started at a same time the distance between them will be 1300 mi exactly after an hour (1 hour).

(1200 m/h) ^2 + (500 m/h) ^2 = (1300 m) ^2

Time is 1 Hour

So the distance between the boat heads and steamer heads if they started the same time and be 1300 mi is 1 hour.