rowing rate per hour

Question

a boat crew rowed 90 kilometers downstream,with the current,in 10 hours. the return trip upstream , against the current,ccovered the same distance, and it took 18 hours. find the crew's rowing rate in still water.

 

 

 

rowing rate=           kilometers per hour

Answer 1

Hello, Machelle,                                 Question:  Find the crew's rowing rate in still water

 

Let x= crew's rowing rate in still water

     y=rate of current  

                                                                                                        Note:  The distance is the same.

 

Make a table to organize your data:                                                    When rowing with the current, the speed

                                                                                                        increases by the speed of the current.

                                                                                                       When rowing against the current, the speed

Crew with             rate       *         time           d (distance)                  is decreased by the speed of the current. 

current              (x+y)                  10 hours       90 km    

_______________________________________________

 

crew against      (x-y)                   18 hours        90 km

current_________________________________________________

 

 

Next, set up a system of two equations from the data in the table:   

   

(x+y)10 =90        Simplify first equation by dividing both sides of equal sign by 10.   

(x-y)18=90          Simplify second equation by dividing both sides by 18.  

             

Solve for "x," and, if you solve for "y," you will be able to check your work.

 

I will let you finish your problem.  I hope that I have helped.  Susan C.