Question 1154015

It takes a boat 2 hours to travel 28 miles downstream and 4 hours to travel 24 miles upstream. 

What is the speed of the boat in still water? 
The boat travels at_____ miles per hour in still water. 

What is the speed of the current of the river? 
The speed of the current is ____miles per hour.
<pre>Let speed of boat in still water be S, and speed of current, C
Then overall speed traveling downstream: {{{matrix(1,10, S + C, "=", 28/2, "____",S + C, "=", 14, "-----", eq, "(i)")}}}
Also, overall speed traveling upstream:  {{{matrix(1,10, S - C, "=", 24/4, "____", S - C, "=", 6, "------", eq, "(ii)")}}}
2S = 20 ----- Adding eqs (ii) & (i)
S, or {{{highlight_green(matrix(1,9, Speed, in, still, water, "=", 20/2, "=", 10, mph))}}}
Try and determine the speed of the current on your own!