Two trains A and B are travelling in the same direction, with train A behind train B. Train A, 65 meters long is travelling at 240 kph. Train B, 85 meters long, is travelling at 120 kph.  

47.  At  when  certain  instant,  the  trains  are  200  m  apart  (clear distance)
a.  6.5sec
b.  5sec
c.  6sec
d.  7sec

48.  . Find the time when train A starts to overtake train B?
a.  6.5sec
b.  5 sec
c.  10.5sec
d.  11 sec
49.  Find  the  distance  travelled  by  train  A  when  it  completely overtakes train B?
a.  700m
b.  650m
c.  600m
d.  550m

50.  Find  the  distance  of  the  following  points  in  three‐dimensional space: (0,0,0) and (5,6,7).
a.  10.49
b.  12.76
c.  11.76
d.  9.54