19.Two trains 200 m and 150 m long are running on parallel rails at the rate of 40 kmph and 45 kmph respectively. In how much time will they cross each other, if they are running in the same direction ?
A. 72 sec B. 132 sec
C. 192 sec D. 252 sec
Answer:D
Relative Speed = (45 - 40 ) Kmph
= 5 kmph
=(5 x 5 / 18)m/sec
= (25 / 18 ) m/sec
Time taken = (350 x 18 / 25) sec
= 252 sec.
