FCFS
             
P1 waited... 0
P2 waited... 10
P3 waited... 39
P4 waited... 42
P5 waited... 49
===============
            140/5 == 28ms

SJF

P1 waited... 10
P2 waited... 32
P3 waited...  0
P4 waited...  3
P5 waited... 20
---------------
             65/5 = 13ms

RR

P1 waited... 0               0
P2 waited... 10+3+7+10+2    32
P3 waited... 10+10          20
P4 waited... 10+10+3        23
P5 waited..  10+10+3+7+10   40
------------------------------
                           115/5=23ms