Question 83155
Let x be time taken upstream and y time taken downstream.

Total number of hours  is:  x + y = 6hrs

Given speed upstream is 2miles per hour and speed downstream is 4 miles per hour.

the distance traveled upstream  = distance traveled downstream

==>speed upstream * time taken  = speed downstream * time taken          

2 *x       = 4 * y  

Substitute for y in the above

2 * x   =   4 * (6-x)

2(x) = 24 - 4x

6x = 24

x = 24 /6

x = 4hrs


The time taken upstream is 4hrs

we know that..

distance traveled upstream =  speed upstream   * time taken
                           =  2 * 4 =  8 miles


Distance traveled upstream is 8 miles