Adapting a classic crossing puzzle

[BMAD 63]

5 college students need to cross a river in a small boat.  Two of these students are on the rowing team and can cross it in one minute if either one or both are rowing.  The other three are not and will take four minutes to cross even if they are with the rowing team members.  The boat can only hold up to three people at a time.  What is the shortest amount of time it will take to cross the river?

[Slashpuzzler 0]

Ok , NOW  I got it ,

Spoiler

8 mins  is the fastest
lets consider fast rower as r  , and slower as s ,    and   | |   be the bridge 
sssrr  |  |                                     0 min
 sss     |  |    rr                             1 min
 sssr   |  |   r                                2 min
       r    |  |    sssr                        6 min
      rr   |  |   sss                           7 min 
            |  |   sssrr                        8 min

 

Edited January 9, 2018 by Slashpuzzler

[Slashpuzzler 0]

After going through a few ways to cross the river , shortest time is 

Spoiler

9 mins

 

[BMAD 63]

there is a faster time

[Donald Cartmill 2]

9 minutes;  i.e. 1 rower & 2 non rowers  cross in 4 minutes ; 1 rower returns in 1 minute ;  2 rowers and 1 non rower cross in 4 minutes.

[CaptainEd 21]

Good job slashpuzzler! And neat puzzle BMAD!