Question

Train X passes a pole in 18 seconds and a platform of length 300 m in 30 seconds. Another train Y passes a pole in 12 seconds. When the two trains run in opposite directions, they completely cross each other in 16 seconds. Find: (i) The length of each train (ii) The speed of train Y in km/h. Choose the correct options:-

Q: Answer-Train X passes a pole in 18 seconds and a platform of length 300 m in 30 seconds. Another train Y pa...

ATQ, Let length of train X Lx metres, speed Sx ms. From passes a pole in 18 s Lx Sx 18 Lx 18 Sx. From passes 300 m platform in 30 s Lx 300 Sx 30 18Sx 300Sx 30 18 300Sx 30 300Sx 12 Sx 25 ms. Then Lx 18 25 450 m. Train Y Let length Ly m, speed Sy ms. From passes a pole in 12 s Ly Sy 12 Ly 12 Sy. When crossing each other in opposite directions in 16 s Lx Ly Sx Sy 16 Substitute Lx, Ly, Sx 450 12Sy 25 Sy 16 450 12Sy 1625 Sy 450 12Sy 400 16Sy 12Sy 16Sy 400 450 4Sy 50 Sy 12.5 ms. Then Ly 12 12.5 150 m. Convert Sy to kmh 1 ms 3.6 kmh Sy 12.5 3.6 45 kmh. Answer i Lengths Train X 450 m Train Y 150 m. ii Speed of train Y 45 kmh.

A (i) Lengths: Train X = 400 m; Train Y = 150 m. (ii) Speed of train Y = 45 km/h.
B (i) Lengths: Train X = 250 m; Train Y = 100 m. (ii) Speed of train Y = 15 km/h.
C (i) Lengths: Train X = 350 m; Train Y = 100 m. (ii) Speed of train Y = 35 km/h.
D (i) Lengths: Train X = 450 m; Train Y = 150 m. (ii) Speed of train Y = 45 km/h.
E None of these