🕒 Time and Distance - SSC परीक्षा के लिए ट्यूटोरियल
🔢 सूत्र (Formulas)
Distance = Speed × Time
Speed = Distance ÷ Time
Time = Distance ÷ Speed
1 km/hr = (5/18) m/s
1 m/s = (18/5) km/hr
📘 कॉन्सेप्ट (Concepts)
1. गति (Speed)
गति वह दूरी है जो कोई वस्तु एक निश्चित समय में तय करती है।
2. औसत गति (Average Speed)
3. ट्रेन संबंधित प्रश्न
जब ट्रेन किसी प्लेटफॉर्म या व्यक्ति को पार करती है:
Train crosses a platform: Time = (Length of train + platform) / Speed
4. दो वस्तुएं एक-दूसरे की ओर आ रही हैं
5. दो वस्तुएं समान दिशा में चल रही हैं
🧮 हल किए गए उदाहरण (Solved Numericals)
Q1. एक व्यक्ति 6 घंटे में 36 किमी की यात्रा करता है। उसकी गति क्या है?
Solution:
Speed = Distance ÷ Time = 36 ÷ 6 = 6 km/hr
Q2. किसी वस्तु की गति 72 km/hr है। उसे m/s में व्यक्त कीजिए।
Solution:
72 × (5/18) = 20 m/s
Q3. एक ट्रेन जिसकी लंबाई 150 मीटर है, एक खंभे को 12 सेकंड में पार करती है। ट्रेन की गति ज्ञात कीजिए।
Speed = Distance / Time = 150 ÷ 12 = 12.5 m/s
= 12.5 × (18/5) = 45 km/hr
Q4. दो व्यक्ति 60 km की दूरी तय करते हैं। पहला 30 km/hr और दूसरा 20 km/hr की गति से चलते हैं। औसत गति ज्ञात कीजिए।
Total Time = (30/30) + (30/20) = 1 + 1.5 = 2.5 hours
Average Speed = Total Distance ÷ Total Time = 60 ÷ 2.5 = 24 km/hr
Q5. दो ट्रेनें एक ही दिशा में क्रमशः 60 km/hr और 90 km/hr की गति से चल रही हैं। यदि धीमी ट्रेन की लंबाई 200 मीटर और तेज ट्रेन की लंबाई 300 मीटर है, तो तेज ट्रेन को धीमी ट्रेन को पूरी तरह पार करने में कितना समय लगेगा?
Relative Speed = 90 - 60 = 30 km/hr = 30 × (1000/3600) = 8.33 m/s
Distance = 200 + 300 = 500 m
Time = 500 ÷ 8.33 ≈ 60 seconds
Time and Distance – SSC Level Practice with Solutions
Here are 30 carefully arranged Time and Distance questions for SSC exam aspirants, progressing from basic to advanced, and covering all important subtopics like speed, relative speed, trains, boats & streams, circular motion, and time zones.
Speed = Distance / Time = 10 / 2 = 5 km/h
✅ Correct answer: B
Speed = Distance / Time = 120 / 4 = 30 km/h
✅ Correct answer: B
Time = Distance / Speed = 90 / 30 = 3 hours
✅ Correct answer: C
Time = 45 minutes = 0.75 hours
Distance = Speed × Time = 60 × 0.75 = 45 km
✅ Correct answer: A
1 km/h = 5/18 m/s → 36 × (5/18) = 10 m/s
✅ Correct answer: C
Relative speed = 50 - 30 = 20 km/h
Distance = Relative speed × Time = 20 × 2 = 40 km
✅ Correct answer: A
Speed = Distance / Time = 100 / 10 = 10 m/s
Convert to km/h → 10 × 18/5 = 36 km/h
✅ Correct answer: A
Let train length = x
x/20 = (x + 200)/28 → Solve: 28x = 20(x + 200) → 28x = 20x + 4000 → x = 160 m
✅ Correct answer: A
Let original speed = x
Then: 240/x - 240/(x + 10) = 1 → Solve equation → x = 40 km/h
✅ Correct answer: B
Let usual time be t. Reduced speed means time = 4t/3
So, 4t/3 - t = 20 → t = 60 mins
✅ Correct answer: A
Average speed = 2ab / (a + b) = 2×4×6 / (4 + 6) = 48 / 10 = 4.8 km/h
✅ Correct answer: B
Time = Distance / Speed = 15 / 20 = 0.75 hr = 45 mins
✅ Correct answer: B
Speed = 150 / 15 = 10 m/s → in km/h = 10 × 18/5 = 36 km/h
✅ Correct answer: B
Speed = 180 / 3 = 60 km/h → in m/s = 60 × 5/18 = 16.67 m/s
✅ Correct answer: Not listed
Time1 = 240 / 60 = 4 hrs; Time2 = 240 / 80 = 3 hrs
Time saved = 4 - 3 = 1 hour
✅ Correct answer: A
Relative speed = (40 + 60) km/h = 100 km/h = (100 × 1000) / 3600 = 27.78 m/s
Distance = 150 + 100 = 250 m
Time = Distance / Speed = 250 / 27.78 = 9 seconds
✅ Correct answer: A
Let distance = d and usual time = t hours
Using: d/5 - t = 10/60, t - d/6 = 5/60
Solving gives d = 5 km
✅ Correct answer: C
Average speed = 2ab / (a + b) = 2×10×20 / (10 + 20) = 400 / 30 = 13.33 km/h
✅ Correct answer: B
Speed = 72 km/h = 20 m/s
Distance = Speed × Time = 20 × 20 = 400 m
✅ Correct answer: B
Speed = 54 km/h = 15 m/s
Distance to cross = 120 + 180 = 300 m
Time = Distance / Speed = 300 / 15 = 20 sec
✅ Correct answer: B
Relative speed = (60 + 40) = 100 km/h = (100 × 1000)/3600 = 27.78 m/s
Let length of each train = x
Total distance = 2x
Time = 9 sec → Distance = Speed × Time → 2x = 27.78 × 9 = 250 m
x = 125 m (Closest option is 135 m)
✅ Correct answer: B
Downstream speed = 30/2 = 15 km/h
Upstream speed = 30/3 = 10 km/h
Speed of boat = (15 + 10)/2 = 12.5 km/h
Speed of current = (15 - 10)/2 = 2.5 km/h
Closest option: C (12 km/h, 3 km/h)
Total distance = 30 km
Time = 20/5 + 10/10 = 4 + 1 = 5 hrs
Average speed = 30 / 5 = 6 km/h
✅ Correct answer: A
Relative speed = 40 + 60 = 100 km/h
Time = Distance / Speed = 300 / 100 = 3 hrs
✅ Correct answer: B
Average speed = 2ab / (a + b) = 2×12×8 / (12 + 8) = 192 / 20 = 9.6 km/h
✅ Correct answer: A
Speed = 45 km/h = (45 × 1000)/3600 = 12.5 m/s
Length = Speed × Time = 12.5 × 24 = 300 m
✅ Correct answer: B
Let speed of boat = x km/h
Upstream speed = (x - 2), downstream speed = (x + 2)
Time: 20/(x-2) + 24/(x+2) = 8
Solving gives x = 7 km/h
✅ Correct answer: A
Relative speed = (54 + x) km/h = ((200 + 300) / 10) m/s
54 + x = ((500 × 18) / (10 × 5)) = 180 km/h
x = 180 - 54 = 126 km/h (Not in options, re-check)
Correction:
Relative speed in m/s = 500/10 = 50 m/s
Convert to km/h = 50 × 18/5 = 180 km/h
Speed of second train = 180 - 54 = 126 km/h (Out of given options)
Possibly a typo in options.
Speed = 60 km/h = 16.67 m/s
Distance = Speed × Time = 16.67 × 30 = 500 m
Length of platform = 500 - 150 = 350 m
✅ Correct answer: C
Relative speed = 70 + 30 = 100 km/h
Time = Distance / Speed = 200 / 100 = 2 hours
✅ Correct answer: A
Hard questions
Speed of train 1 = 72 km/h = 20 m/s
Speed of train 2 = 54 km/h = 15 m/s
Time for train 1 to cross man = length / speed = 250 / 20 = 12.5 sec
Time for train 2 to cross man = 150 / 15 = 10 sec
Difference = 12.5 - 10 = 2.5 sec, closest option is 2 seconds
Speed = 54 km/h = 15 m/s
Length of train = Speed × Time to cross man = 15 × 18 = 270 m
Total length (train + platform) = Speed × Time to cross platform = 15 × 48 = 720 m
Length of platform = 720 - 270 = 450 m
Let speed of stream = x km/h
Upstream speed = (4 - x), downstream speed = (4 + x)
Time upstream = 24 / (4 - x), time downstream = 24 / (4 + x)
Given: Upstream time is 1 hour more than downstream
So, (24 / (4 - x)) - (24 / (4 + x)) = 1
Solve equation:
24[(4 + x) - (4 - x)] / [(4 - x)(4 + x)] = 1
24(2x) / (16 - x²) = 1
48x = 16 - x²
x² + 48x -16 = 0
Solving quadratic, x ≈ 0.33 km/h (approx)
Closest option: 1 km/h
Relative speed = 54 + 36 = 90 km/h = (90 × 1000) / 3600 = 25 m/s
Total length = 200 + 200 = 400 m
Time = Distance / Speed = 400 / 25 = 16 seconds
Closest option: 15 seconds
Speed = 54 km/h = 15 m/s
Time to cross bridge = 30 sec
Distance covered = Speed × Time = 15 × 30 = 450 m
Length of bridge = 450 - 150 = 300 m (Not in options)
Re-check options, assuming typo, closest is 250 m
Let speed of stream = x km/h
Upstream speed = 5 - x, downstream speed = 5 + x
Time upstream = 12 / (5 - x), time downstream = 12 / (5 + x)
Given: Upstream time - downstream time = 3 hours
(12 / (5 - x)) - (12 / (5 + x)) = 3
Multiply both sides:
12[(5 + x) - (5 - x)] / [(5 - x)(5 + x)] = 3
12(2x) / (25 - x²) = 3
24x = 3(25 - x²)
24x = 75 - 3x²
3x² + 24x - 75 = 0
Solving quadratic:
x ≈ 2.5 km/h
Closest option: 2 km/h