Train Problem set 1
Important Train Based Formulas : Click Here
Q. A train crosses a person in 18 seconds and a 450 m long platform in 48 seconds. Find the length of the train. āĻĒā§ā§°āĻļā§āύ: āĻāĻāύ ā§°ā§'āϞ⧠āĻāĻāύ āĻŦā§āϝāĻā§āϤāĻŋāĻ 18 āĻā§āĻā§āĻŖā§āĻĄāϤ āĻā§°ā§ 450 āĻŽāĻŋāĻāĻžā§° āĻĻā§āĻāϞ āĻāĻāĻž āĻĒā§āϞā§āĻāĻĢā§°ā§āĻŽāĻ 48 āĻā§āĻā§āĻŖā§āĻĄāϤ āĻĒāĻžā§° āĻšāϝāĻŧāĨ¤ ā§°ā§'āϞāĻāύ⧰ āĻĻā§ā§°ā§āĻā§āϝ āĻāĻŋāĻŽāĻžāύ ?
A) 250 m B) 270 m C) 300 m D) 320 m
Solution / āϏāĻŽāĻžāϧāĻžāύ
Let the length of the train = L metres (āϧ⧰āĻž āĻšāĻāĻ, ā§°ā§'āϞāĻāύ⧰ āĻĻā§ā§°ā§āĻā§āϝ = L āĻŽāĻŋāĻāĻžā§°)
Situation 1 / āĻĒā§°āĻŋāϏā§āĻĨāĻŋāϤāĻŋ 1:
When the train crosses a person:
Situation 2 / āĻĒā§°āĻŋāϏā§āĻĨāĻŋāϤāĻŋ 2:
When the train crosses the platform:
Since the speed is the same:
Cross multiply / Cross multiplication:
Trick / āĻāĻŽā§ āĻā§ā§°āĻŋāĻ
Time difference:
The extra 30 seconds is required to cover the 450 m platform.
So,
Train length:
Ans / āĻāϤā§āϤ⧰: B) 270 metres / 270 āĻŽāĻŋāĻāĻžā§°
Shortcut Formula / āĻāĻŽā§ āϏā§āϤā§ā§°: Train Length = Platform Length × Person Crossing Time / Platform Crossing Time − Person Crossing Timeâ
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Practice Set — Trains / āĻ āύā§āĻļā§āϞāύā§
Q1. A train crosses a person in 15 seconds and a 300 m long platform in 35 seconds. Find the length of the train. (āĻāĻāύ ā§°ā§'āϞ⧠āĻāĻāύ āĻŦā§āϝāĻā§āϤāĻŋāĻ 15 āĻā§āĻā§āĻŖā§āĻĄāϤ āĻā§°ā§ 300 āĻŽāĻŋāĻāĻžā§° āĻĻā§āĻāϞ āĻĒā§āϞā§āĻāĻĢā§°ā§āĻŽāĻ 35 āĻā§āĻā§āĻŖā§āĻĄāϤ āĻĒāĻžā§° āĻšāϝāĻŧāĨ¤ ā§°ā§'āϞāĻāύ⧰ āĻĻā§ā§°ā§āĻā§āϝ āĻāĻŋāĻŽāĻžāύ ?)
A) 200 m B) 225 m C) 250 m D) 275 m
Q2. A train crosses a person in 20 seconds and a 400 m long platform in 45 seconds. Find the length of the train. (āĻāĻāύ ā§°ā§'āϞ⧠āĻāĻāύ āĻŦā§āϝāĻā§āϤāĻŋāĻ 20 āĻā§āĻā§āĻŖā§āĻĄāϤ āĻā§°ā§ 400 āĻŽāĻŋāĻāĻžā§° āĻĻā§āĻāϞ āĻĒā§āϞā§āĻāĻĢā§°ā§āĻŽāĻ 45 āĻā§āĻā§āĻŖā§āĻĄāϤ āĻĒāĻžā§° āĻšāϝāĻŧāĨ¤ ā§°ā§'āϞāĻāύ⧰ āĻĻā§ā§°ā§āĻā§āϝ āĻāĻŋāĻŽāĻžāύ ?)
A) 280 m B) 300 m C) 320 m D) 350 m
Q3. A train crosses a person in 18 seconds and a 450 m long platform in 48 seconds. Find the length of the train. (āĻāĻāύ ā§°ā§'āϞ⧠āĻāĻāύ āĻŦā§āϝāĻā§āϤāĻŋāĻ 18 āĻā§āĻā§āĻŖā§āĻĄāϤ āĻā§°ā§ 450 āĻŽāĻŋāĻāĻžā§° āĻĻā§āĻāϞ āĻĒā§āϞā§āĻāĻĢā§°ā§āĻŽāĻ 48 āĻā§āĻā§āĻŖā§āĻĄāϤ āĻĒāĻžā§° āĻšāϝāĻŧāĨ¤ ā§°ā§'āϞāĻāύ⧰ āĻĻā§ā§°ā§āĻā§āϝ āĻāĻŋāĻŽāĻžāύ ?)
A) 250 m B) 270 m C) 300 m D) 320 m
Q4. A train crosses a person in 12 seconds and a 360 m long platform in 30 seconds. Find the length of the train. (āĻāĻāύ ā§°ā§'āϞ⧠āĻāĻāύ āĻŦā§āϝāĻā§āϤāĻŋāĻ 12 āĻā§āĻā§āĻŖā§āĻĄāϤ āĻā§°ā§ 360 āĻŽāĻŋāĻāĻžā§° āĻĻā§āĻāϞ āĻĒā§āϞā§āĻāĻĢā§°ā§āĻŽāĻ 30 āĻā§āĻā§āĻŖā§āĻĄāϤ āĻĒāĻžā§° āĻšāϝāĻŧāĨ¤ ā§°ā§'āϞāĻāύ⧰ āĻĻā§ā§°ā§āĻā§āϝ āĻāĻŋāĻŽāĻžāύ ?)
A) 200 m B) 220 m C) 240 m D) 260 m
Q5. A train crosses a person in 25 seconds and a 500 m long platform in 45 seconds. Find the length of the train. (āĻāĻāύ ā§°ā§'āϞ⧠āĻāĻāύ āĻŦā§āϝāĻā§āϤāĻŋāĻ 25 āĻā§āĻā§āĻŖā§āĻĄāϤ āĻā§°ā§ 500 āĻŽāĻŋāĻāĻžā§° āĻĻā§āĻāϞ āĻĒā§āϞā§āĻāĻĢā§°ā§āĻŽāĻ 45 āĻā§āĻā§āĻŖā§āĻĄāϤ āĻĒāĻžā§° āĻšāϝāĻŧāĨ¤ ā§°ā§'āϞāĻāύ⧰ āĻĻā§ā§°ā§āĻā§āϝ āĻāĻŋāĻŽāĻžāύ ?)
A) 500 m B) 550 m C) 600 m D) 625 m
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Q1. A train running at 108 km/h crosses a 480 m long platform in 32 seconds. What is the length of the train ? (āĻāĻāύ ā§°ā§'āϞāĻāĻžāĻĄāĻŧā§āϝāĻŧā§ 108 āĻāĻŋāĻŽāĻŋ/āĻāĻŖā§āĻāĻž āĻŦā§āĻā§ā§°ā§ 480 āĻŽāĻŋāĻāĻžā§° āĻĻā§āĻāϞ āĻĒā§āϞā§āĻāĻĢā§°ā§āĻŽ āĻāĻāĻž 32 āĻā§āĻā§āĻŖā§āĻĄāϤ āĻĒāĻžā§° āĻšāϝāĻŧāĨ¤ ā§°ā§'āϞāĻāĻžāĻĄāĻŧā§āĻāύ⧰ āĻĻā§ā§°ā§āĻā§āϝ āĻāĻŋāĻŽāĻžāύ ?)
Options / āĻŦāĻŋāĻāϞā§āĻĒ: A) 420 m B) 450 m C) 480 m D) 500 m
Solution / āϏāĻŽāĻžāϧāĻžāύ
Speed / āĻŦā§āĻ: 108 km/h = 108 × 5/18 = 30 m/s
Total distance / āĻŽā§āĻ āĻĻā§ā§°āϤā§āĻŦ:
= Speed × Time
= 30 × 32
= 960 m
When a train crosses a platform:
Total distance = Train length + Platform length (āĻŽā§āĻ āĻĻā§ā§°āϤā§āĻŦ = ā§°ā§'āϞāĻāĻžāĻĄāĻŧā§ā§° āĻĻā§ā§°ā§āĻā§āϝ + āĻĒā§āϞā§āĻāĻĢā§°ā§āĻŽā§° āĻĻā§ā§°ā§āĻā§āϝ)
Therefore,
Train length = 960 − 480 = 480 m
Ans / āĻāϤā§āϤ⧰: C) 480 metres / 480 āĻŽāĻŋāĻāĻžā§°
Practice Question / āĻ āύā§āĻļā§āϞāύā§
Q. A train running at 72 km/h crosses a 300 m long bridge in 25 seconds. What is the length of the train ? (āĻāĻāύ ā§°ā§'āϞāĻāĻžāĻĄāĻŧā§āϝāĻŧā§ 72 āĻāĻŋāĻŽāĻŋ/āĻāĻŖā§āĻāĻž āĻŦā§āĻā§ā§°ā§ 300 āĻŽāĻŋāĻāĻžā§° āĻĻā§āĻāϞ āĻĻāϞāĻ āĻāĻāύ 25 āĻā§āĻā§āĻŖā§āĻĄāϤ āĻĒāĻžā§° āĻšāϝāĻŧāĨ¤ ā§°ā§'āϞāĻāĻžāĻĄāĻŧā§āĻāύ⧰ āĻĻā§ā§°ā§āĻā§āϝ āĻāĻŋāĻŽāĻžāύ ?)
Options / āĻŦāĻŋāĻāϞā§āĻĒ: A) 200 m B) 220 m C) 250 m D) 280 m
Solution / āϏāĻŽāĻžāϧāĻžāύ
72 km/h = 72 × 5/18 = 20 m/s
Total distance = 20 × 25 = 500 m
Train length = Total distance − Bridge length
= 500 − 300
= 200 m
Ans / āĻāϤā§āϤ⧰: A) 200 metres / 200 āĻŽāĻŋāĻāĻžā§°
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Train & Platform — Practice Set
Q1. A train running at 108 km/h crosses a 480 m long platform in 32 seconds. What is the length of the train ? (āĻāĻāύ ā§°ā§'āϞāĻāĻžāĻĄāĻŧā§āϝāĻŧā§ 108 āĻāĻŋāĻŽāĻŋ/āĻāĻŖā§āĻāĻž āĻŦā§āĻā§ā§°ā§ 480 āĻŽāĻŋāĻāĻžā§° āĻĻā§āĻāϞ āĻĒā§āϞā§āĻāĻĢā§°ā§āĻŽ āĻāĻāĻž 32 āĻā§āĻā§āĻŖā§āĻĄāϤ āĻĒāĻžā§° āĻšāϝāĻŧāĨ¤ ā§°ā§'āϞāĻāĻžāĻĄāĻŧā§āĻāύ⧰ āĻĻā§ā§°ā§āĻā§āϝ āĻāĻŋāĻŽāĻžāύ ?)
A) 420 m B) 450 m C) 480 m D) 500 m
Q2. A train running at 72 km/h crosses a 300 m long platform in 25 seconds. What is the length of the train ? (āĻāĻāύ ā§°ā§'āϞāĻāĻžāĻĄāĻŧā§āϝāĻŧā§ 72 āĻāĻŋāĻŽāĻŋ/āĻāĻŖā§āĻāĻž āĻŦā§āĻā§ā§°ā§ 300 āĻŽāĻŋāĻāĻžā§° āĻĻā§āĻāϞ āĻĒā§āϞā§āĻāĻĢā§°ā§āĻŽ āĻāĻāĻž 25 āĻā§āĻā§āĻŖā§āĻĄāϤ āĻĒāĻžā§° āĻšāϝāĻŧāĨ¤ ā§°ā§'āϞāĻāĻžāĻĄāĻŧā§āĻāύ⧰ āĻĻā§ā§°ā§āĻā§āϝ āĻāĻŋāĻŽāĻžāύ ?)
A) 180 m B) 200 m C) 220 m D) 250 m
Q3. A train running at 90 km/h crosses a 350 m long platform in 24 seconds. What is the length of the train ? (āĻāĻāύ ā§°ā§'āϞāĻāĻžāĻĄāĻŧā§āϝāĻŧā§ 90 āĻāĻŋāĻŽāĻŋ/āĻāĻŖā§āĻāĻž āĻŦā§āĻā§ā§°ā§ 350 āĻŽāĻŋāĻāĻžā§° āĻĻā§āĻāϞ āĻĒā§āϞā§āĻāĻĢā§°ā§āĻŽ āĻāĻāĻž 24 āĻā§āĻā§āĻŖā§āĻĄāϤ āĻĒāĻžā§° āĻšāϝāĻŧāĨ¤ ā§°ā§'āϞāĻāĻžāĻĄāĻŧā§āĻāύ⧰ āĻĻā§ā§°ā§āĻā§āϝ āĻāĻŋāĻŽāĻžāύ ?)
A) 200 m B) 225 m C) 250 m D) 275 m
Q4. A train running at 54 km/h crosses a 250 m long platform in 30 seconds. What is the length of the train ? (āĻāĻāύ ā§°ā§'āϞāĻāĻžāĻĄāĻŧā§āϝāĻŧā§ 54 āĻāĻŋāĻŽāĻŋ/āĻāĻŖā§āĻāĻž āĻŦā§āĻā§ā§°ā§ 250 āĻŽāĻŋāĻāĻžā§° āĻĻā§āĻāϞ āĻĒā§āϞā§āĻāĻĢā§°ā§āĻŽ āĻāĻāĻž 30 āĻā§āĻā§āĻŖā§āĻĄāϤ āĻĒāĻžā§° āĻšāϝāĻŧāĨ¤ ā§°ā§'āϞāĻāĻžāĻĄāĻŧā§āĻāύ⧰ āĻĻā§ā§°ā§āĻā§āϝ āĻāĻŋāĻŽāĻžāύ ?)
A) 150 m B) 175 m C) 200 m D) 225 m
Q5. A train running at 81 km/h crosses a 400 m long platform in 30 seconds. What is the length of the train ? (āĻāĻāύ ā§°ā§'āϞāĻāĻžāĻĄāĻŧā§āϝāĻŧā§ 81 āĻāĻŋāĻŽāĻŋ/āĻāĻŖā§āĻāĻž āĻŦā§āĻā§ā§°ā§ 400 āĻŽāĻŋāĻāĻžā§° āĻĻā§āĻāϞ āĻĒā§āϞā§āĻāĻĢā§°ā§āĻŽ āĻāĻāĻž 30 āĻā§āĻā§āĻŖā§āĻĄāϤ āĻĒāĻžā§° āĻšāϝāĻŧāĨ¤ ā§°ā§'āϞāĻāĻžāĻĄāĻŧā§āĻāύ⧰ āĻĻā§ā§°ā§āĻā§āϝ āĻāĻŋāĻŽāĻžāύ ?)
A) 225 m B) 250 m C) 275 m D) 300 m