IBPS RRB Officer Prelims 09 Sep 2017 Shift 1 Paper

(4) Rate downstream of boat
=[

9.6 36

60

]= kmph.
=[

9.6×60

36

]= kmph.
= 16 kmph.
Speed of current = 1.6 kmph.
∴ Speed of boat in still water
= (16 – 1.6) kmph.
= 14.4 kmph.
∴ Rate upstream of boat
= (14.4 – 1.6) kmph.
= 12.8kmph.
∴ Required time=[

19.2

12.8

].hours = 1.5 hours