Student: How long does a train 100 m long traveling at 72 kmph takes to cross a tunnel of 1400 m in length?\nOptions:\n(A) 70 sec\n(B) 60sec\n(C) 82 sec\n(D) 75 sec\n(E) 62 sec.
Another student: Let's say, hmmm...

User
D = 1400+100 = 1500 m\nS = 72 * 5/18 = 20\nT = 1500 * 1/20 = 75 sec Final answer: (D).
Assistant