August 26th, 2018, 11:21 PM  #1 
Senior Member Joined: Aug 2014 From: India Posts: 343 Thanks: 1  what is the value of C ?
The speed of the boat in still water is 22 kmph. It takes the same time for the boat to travel 1.2 km upstream as it does to travel 32km downstream. What is the speed of the current? Solution: The overall speed of boat going downstream will be speed downstream = 22 + c The overall speed of boat going upstream will be speed of boat MINUS speed of current, because boat and current are pointing in opposite directions. speed upstream = 22 – c The typical equation for distance, rate, and time can be used. distance downstream = rate downstream * time 32 km = (22 + c) * t distance upstream = rate upstream * time 1.2 km = (22 – c) * t It seems almost impossible to answer, since we do not know what t is. But you could solve each equation for t. Then equate the results, because same t value is used in both. 32 km / (22 + c) = t 1.2 km / (22 – c) = t So if both things equal t, they equal each other. 32 km / (22 + c) = 1.2 km / (22 – c) C = 20.4 But C value is 10 kmph. how to solve this problem ? 
August 27th, 2018, 12:21 AM  #2 
Global Moderator Joined: Dec 2006 Posts: 20,285 Thanks: 1968 
It seems that the 1.2 km given in the problem should have been 12 km.

August 27th, 2018, 03:09 AM  #3 
Senior Member Joined: Aug 2014 From: India Posts: 343 Thanks: 1  
August 27th, 2018, 05:09 AM  #4 
Global Moderator Joined: Dec 2006 Posts: 20,285 Thanks: 1968 
Because 12 km would lead to c = 10 km/h.

August 27th, 2018, 06:13 AM  #5 
Math Team Joined: Oct 2011 From: Ottawa Ontario, Canada Posts: 13,961 Thanks: 991 
c = current speed @22+c..........................32................. ...........>h hours [downstream] @22 c............12...........>h hours [upstream] 32 / (22+c) = 12 / (22c) Solve for c 