Select the correct answer. a boat takes 8 hours to go 6 miles upstream and come back to the starting point. if the speed of the boat is 4 miles per hour in still water, what is the rate of the current? hint: total time taken = time taken to go upstream + time taken to go downstream `"time taken to go upstream" = "distance"/"speed of boat in still water + rate of current"` ` ` `"time taken to go downstream" = "distance"/"speed of boat in still water - rate of current"`