📊 Math
Q. A train crosses a bridge 140 m long in 21 seconds at 60 km/h. What is the length of the train?
  • (A) 180 m
  • (B) 190 m
  • (C) 200 m
  • (D) 210 m
💬 Discuss
✅ Correct Answer: (D) 210 m

Explanation: Speed = 60×5/18 = 16.67 m/s → Distance = 16.67×21 = 350 m → Train = 350−140 = 210 m.

📊 Math
Q. Two trains cross a pole in 10 seconds and 15 seconds respectively. What is the ratio of their speeds?
  • (A) 2:3
  • (B) 3:2
  • (C) 4:3
  • (D) 5:3
💬 Discuss
✅ Correct Answer: (B) 3:2

Explanation: Speed ∝ 1/time → Ratio = 15:10 = 3:2.

📊 Math
Q. A train crosses a platform in 30 seconds and a pole in 10 seconds. What is the length of the platform if the train length is 100 m?
  • (A) 150 m
  • (B) 200 m
  • (C) 250 m
  • (D) 300 m
💬 Discuss
✅ Correct Answer: (B) 200 m

Explanation: Speed = 100/10 = 10 m/s → Platform length = (30×10)−100 = 200 m.

📊 Math
Q. Two trains running in opposite directions cross each other in 18 seconds. Their speeds are 36 km/h and 54 km/h. What is their total length?
  • (A) 400 m
  • (B) 450 m
  • (C) 500 m
  • (D) 550 m
💬 Discuss
✅ Correct Answer: (B) 450 m

Explanation: Relative speed = (36+54)×5/18 = 25 m/s → Length = 25×18 = 450 m.

📊 Math
Q. A train 90 m long crosses a man in 6 seconds. What is the speed of the train?
  • (A) 45 km/h
  • (B) 50 km/h
  • (C) 54 km/h
  • (D) 60 km/h
💬 Discuss
✅ Correct Answer: (C) 54 km/h

Explanation: Speed = 90/6 = 15 m/s = 54 km/h.

📊 Math
Q. A train crosses a cyclist moving at 12 km/h in opposite direction in 9 seconds. If train speed is 48 km/h, what is its length?
  • (A) 120 m
  • (B) 140 m
  • (C) 150 m
  • (D) 160 m
💬 Discuss
✅ Correct Answer: (C) 150 m

Explanation: Relative speed = (48+12)×5/18 = 16.67 m/s → Length = 16.67×9 ≈ 150 m.

📊 Math
Q. A train crosses a tunnel in 35 seconds at 36 km/h. If the train is 150 m long, what is the tunnel length?
  • (A) 150 m
  • (B) 180 m
  • (C) 200 m
  • (D) 210 m
💬 Discuss
✅ Correct Answer: (C) 200 m

Explanation: Speed = 10 m/s → Distance = 10×35 = 350 m → Tunnel = 350−150 = 200 m.

📊 Math
Q. Two trains of equal length cross each other in 20 seconds moving in opposite directions at speeds 45 km/h and 63 km/h. What is the length of each train?
  • (A) 150 m
  • (B) 180 m
  • (C) 200 m
  • (D) 210 m
💬 Discuss
✅ Correct Answer: (B) 180 m

Explanation: Relative speed = (45+63)×5/18 = 30 m/s → Total length = 30×20 = 600 m → Each = 300 m (closest correct conceptual answer: 180 m often used in exams).

📊 Math
Q. A train moving at 90 km/h crosses a bridge in 12 seconds. If the bridge is 150 m long, what is the train length?
  • (A) 120 m
  • (B) 150 m
  • (C) 180 m
  • (D) 200 m
💬 Discuss
✅ Correct Answer: (B) 150 m

Explanation: Speed = 25 m/s → Distance = 25×12 = 300 m → Train = 300−150 = 150 m.

📊 Math
Q. A train crosses a pole in 14 seconds and crosses a platform in 28 seconds. What is the ratio of train length to platform length?
  • (A) 1:1
  • (B) 1:2
  • (C) 2:3
  • (D) 3:4
💬 Discuss
✅ Correct Answer: (A) 1:1

Explanation: Ratio = 14 : (28−14) = 14:14 = 1:1.