Question 498164
two boats leave a port at the same time, one traveling north, one traveling south. the northbound boat goes 12 mph faster than the southbound boat. The southbound boat is going 23 mph, how long will it take for the boats to be 87 miles apart? 
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let x=distance southbound boat traveled
87-x = distance northbound boat traveled 
travel time=distance/speed (equal for both boats)
..
x/23=(87-x)/(23+12)
x/23=(87-x)/35
35x=23(87-x)=2001-23x
58x=2001
x=34.5
x/23=34.5/23=1.5 hrs
..
ans:
It will take 1.5 hrs for the boats to be 87 miles apart