Bob can row 12 mph in still water. The total time to travel downstream and return upstream to the starting point is 4 hours. If the total distance downstream and back is 36 miles, determine the speed of the river (current speed).

Step-by-step explanation:

when Bob travels downstream his speed is 12 + x

where x is the speed of the river

he travels 36/2 = 18 miles

it takes

hours to  do it  

when Bob travels upstream his speed is 12 - x

it takes

hours to  do it  

finally, it takes

So the current speed is 6mph

it takes 1 hour to downstream and 3 hours to upstream

hope this helps

sup

step-by-step explanation:

the answer is y < -3 or   y > 3

-3y > 7 + 2

-3 y > 9

y < -3