Train Problem (Question)



Concept: Two Trains Crossing Each Other āϧāĻžā§°āĻŖāĻž: āĻĻ⧁āϟāĻž ⧰⧇āϞ āĻĒā§°āĻ¸ā§āĻĒā§° āĻ…āϤāĻŋāĻ•ā§ā§°āĻŽ āϕ⧰āĻž


When two trains cross each other, the total distance covered is the sum of their lengths. āϝ⧇āϤāĻŋ⧟āĻž āĻĻ⧁āϟāĻž ⧰⧇āϞ⧇ āĻĒā§°āĻ¸ā§āĻĒā§° āĻ…āϤāĻŋāĻ•ā§ā§°āĻŽ āϕ⧰⧇, āϤ⧇āϤāĻŋ⧟āĻž āĻŽā§āĻ  āĻĻā§‚ā§°āĻ¤ā§āĻŦ āĻš’āϞ āĻĻā§ā§Ÿā§‹ ⧰⧇āϞ⧰ āĻĻā§ˆā§°ā§āĻ˜ā§āϝ⧰ āϝ⧋āĻ—āĻĢāϞāĨ¤


Total distance = L₁ + L₂ : āĻŽā§āĻ  āĻĻā§‚ā§°āĻ¤ā§āĻŦ = L₁ + L₂


Relative Speed (Opposite Direction) : āφāĻĒ⧇āĻ•ā§āώāĻŋāĻ• āĻ—āϤāĻŋ (āĻŦāĻŋāĻĒā§°ā§€āϤ āĻĻāĻŋāĻļāϤ)


If two trains move in opposite directions, their relative speed is the sum of their speeds. āϝāĻĻāĻŋ āĻĻ⧁āϟāĻž ⧰⧇āϞ āĻŦāĻŋāĻĒā§°ā§€āϤ āĻĻāĻŋāĻļāϤ āϚāϞ⧇, āϤ⧇āĻ¨ā§āϤ⧇ āφāĻĒ⧇āĻ•ā§āώāĻŋāĻ• āĻ—āϤāĻŋ āĻš’āϞ āĻĻā§ā§Ÿā§‹ āĻ—āϤāĻŋā§° āϝ⧋āĻ—āĻĢāϞāĨ¤


Relative Speed = S₁ + S₂ : āφāĻĒ⧇āĻ•ā§āώāĻŋāĻ• āĻ—āϤāĻŋ = S₁ + S₂


Time Formula: āϏāĻŽā§Ÿā§° āϏ⧂āĻ¤ā§ā§°


Time = L1 + L2 / S1 + S2 āϏāĻŽā§Ÿ = L1 + L2 / S1 + S2


Given Data : āĻĒā§ā§°āĻĻāĻ¤ā§āϤ āϤāĻĨā§āϝ


Speed of Train 1 (S₁) = 110 m/s : Train 1 ā§° āĻ—āϤāĻŋ = 110 āĻŽāĻŋ/āϛ⧇


Speed of Train 2 (S₂) = 140 m/s : Train 2 ā§° āĻ—āϤāĻŋ = 140 āĻŽāĻŋ/āϛ⧇


S1 + S2 = 110 + 140 = 250 m/s 


Case 1: Numerical Problem : āĻ—āĻŖāĻŋāĻ¤ā§€ā§Ÿ āωāĻĻāĻžāĻšā§°āĻŖ


Length of Train 1 (L₁) = 400 m : Train 1 ā§° āĻĻā§ˆā§°ā§āĻ˜ā§āϝ = 400 āĻŽāĻŋ


Length of Train 2 (L₂) = 600 m : Train 2 ā§° āĻĻā§ˆā§°ā§āĻ˜ā§āϝ = 600 āĻŽāĻŋ


Soln āϏāĻŽāĻžāϧāĻžāύ


L1 + L2 = 400 + 600 = 1000 m L


Time = 1000 / 250 = 4 seconds


Final Answer : āĻšā§‚ā§œāĻžāĻ¨ā§āϤ āωāĻ¤ā§āϤ⧰ : Time taken by the two trains to cross each other = 4 seconds : āĻĻ⧁āϟāĻž ⧰⧇āϞ⧇ āĻĒā§°āĻ¸ā§āĻĒā§° āĻ…āϤāĻŋāĻ•ā§ā§°āĻŽ āϕ⧰āĻŋāĻŦāϞ⧈ āĻ˛ā§‹ā§ąāĻž āϏāĻŽā§Ÿ = ā§Ē āϛ⧇āϕ⧇āĻŖā§āĻĄ


 Key Exam Tips (SSC / HSLC) : āĻĒā§°ā§€āĻ•ā§āώāĻžā§° āϗ⧁⧰⧁āĻ¤ā§āĻŦāĻĒā§‚āĻ°ā§āĻŖ āϟāĻŋāĻĒāĻ›



  • Crossing each other → Add lengths : āĻ…āϤāĻŋāĻ•ā§ā§°āĻŽ āϕ⧰āĻž → āĻĻā§ˆā§°ā§āĻ˜ā§āϝ āϝ⧋āĻ—

  • Opposite direction → Add speeds : āĻŦāĻŋāĻĒā§°ā§€āϤ āĻĻāĻŋāĻļ → āĻ—āϤāĻŋ āϝ⧋āĻ—

  • Same direction → Subtract speeds : āĻāϕ⧇āϟāĻž āĻĻāĻŋāĻļ → āĻ—āϤāĻŋ āĻŦāĻŋā§Ÿā§‹āĻ—

  • km/h to m/s conversion → × 5/18  : km/h ā§° āĻĒā§°āĻž m/s āϞ⧈ → × 5/18