Answer & Explanation
C) 6 m/h
let, speed of Ali=X mph and Faizer=Y mph
Now, relative speed when Ali is walking int the same direction with Faizer= (X-Y)mph
hence, according to question, 27/(X-Y)=9 ; solving X-Y=3; --- (1)
Now relative speed when walking in the opposite direction= (X+Y) mph
hence, according to question, 27/(X+y)=3; solving X+Y=9; --- (2)
solving 1 and 2 we get X=6 and Y=3, where X is the speed of Ali.