<PRE><B>Question 1133894</B>
A motorboat can maintain a constant speed of 13 miles per hour relative to the water.
 The boat makes a trip upstream to a certain point in 45 ​minutes; the return trip takes 33 minutes. What is the speed of the​ current? 
:
let c = the rate of the current
then
(13-c) = ground speed against the current
and
(13+c) = ground speed with
:
Write a distance equation; dist = speed * time
the dist up = the dist back
{{{45/60}}}(13-c) = {{{33/60}}}(13+c)
multiply both sides by 60
45(13-c) = 33(13+c)
585 - 45c = 429 + 33c
585 - 429 = 45c + 33c
156 = 78c
c = 156/78
c = 2 mph is the current</PRE>