Time Speed Distance Solved Examples 2026 (40+ Problems with Solutions)

Last Updated: June 2026

This page collects 40+ solved time, speed, and distance problems at placement-exam difficulty, organized from basics through trains, boats, and average speed. Each problem has a full step-by-step solution. Candidates report time-speed-distance as one of the highest-frequency quantitative topics in TCS NQT, Infosys, and Wipro rounds, so working through these builds directly transferable speed.

Formula Reference

Section A: Basics (Problems 1-12)

Problem 1. A car travels 150 km in 3 hours. Find its speed. Solution: Speed = 150/3 = 50 km/hr.

Problem 2. A cyclist rides at 18 km/hr for 2.5 hours. Find the distance. Solution: Distance = 18 × 2.5 = 45 km.

Problem 3. A runner covers 400 m at 8 m/s. Find the time. Solution: Time = 400/8 = 50 seconds.

Problem 4. Convert 72 km/hr to m/s. Solution: 72 × 5/18 = 20 m/s.

Problem 5. Convert 25 m/s to km/hr. Solution: 25 × 18/5 = 90 km/hr.

Problem 6. A train covers 240 km in 4 hours. What distance in 6 hours at the same speed? Solution: Speed = 60 km/hr, distance = 60 × 6 = 360 km.

Problem 7. A man walks at 5 km/hr. How long to cover 12 km? Solution: Time = 12/5 = 2.4 hours, that is 2 hours 24 minutes.

Problem 8. A bus travels 60 km at 40 km/hr, then 60 km at 60 km/hr. Find total time. Solution: 60/40 + 60/60 = 1.5 + 1 = 2.5 hours.

Problem 9. A car increases speed from 40 to 50 km/hr. By what percentage does travel time fall for a fixed distance? Solution: Time is inversely proportional to speed. New time factor = 40/50 = 0.8, a 20% fall.

Problem 10. Two cars start together, one at 50 km/hr and one at 60 km/hr in the same direction. How far apart after 3 hours? Solution: Relative speed = 10 km/hr, gap = 10 × 3 = 30 km.

Problem 11. A person covers a distance in 6 hours at 10 km/hr. At what speed to cover it in 4 hours? Solution: Distance = 60 km, speed = 60/4 = 15 km/hr.

Problem 12. A train covers 90 km in 1.5 hours. Find its speed in m/s. Solution: 90/1.5 = 60 km/hr = 60 × 5/18 = 16.67 m/s.

Section B: Trains (Problems 13-24)

Problem 13. A train 200 m long crosses a pole in 10 seconds. Find its speed in km/hr. Solution: Speed = 200/10 = 20 m/s = 72 km/hr.

Problem 14. A train 150 m long crosses a 250 m platform in 20 seconds. Find its speed in km/hr. Solution: Distance = 400 m, speed = 400/20 = 20 m/s = 72 km/hr.

Problem 15. A train running at 54 km/hr crosses a pole in 12 seconds. Find its length. Solution: Speed = 15 m/s, length = 15 × 12 = 180 m.

Problem 16. A 180 m train crosses a platform in 27 seconds at 36 km/hr. Find the platform length. Solution: Speed = 10 m/s, total distance = 10 × 27 = 270 m, platform = 270 - 180 = 90 m.

Problem 17. Two trains 120 m and 180 m long run toward each other at 42 and 48 km/hr. Time to cross? Solution: Relative speed = 90 km/hr = 25 m/s, total length = 300 m, time = 300/25 = 12 seconds.

Problem 18. Two trains 100 m and 150 m long run in the same direction at 72 and 54 km/hr. Time for the faster to cross the slower? Solution: Relative speed = 18 km/hr = 5 m/s, total length = 250 m, time = 250/5 = 50 seconds.

Problem 19. A train crosses a man running at 6 km/hr in the same direction in 12 seconds. The train is 200 m long. Find its speed. Solution: Relative speed = 200/12 = 16.67 m/s = 60 km/hr; train speed = 60 + 6 = 66 km/hr.

Problem 20. A train 240 m long passes a 360 m platform in 30 seconds. Find its speed in km/hr. Solution: Distance = 600 m, speed = 600/30 = 20 m/s = 72 km/hr.

Problem 21. A train crosses two platforms 200 m and 300 m in 18 and 24 seconds. Find the train length. Solution: Let length L and speed v. (L + 200)/18 = (L + 300)/24 = v. Cross multiply: 24(L + 200) = 18(L + 300), 24L + 4800 = 18L + 5400, 6L = 600, L = 100 m.

Problem 22. A 150 m train passes a bridge in 15 seconds at 72 km/hr. Find the bridge length. Solution: Speed = 20 m/s, total = 300 m, bridge = 300 - 150 = 150 m.

Problem 23. Two trains of equal length 120 m cross each other in opposite directions in 8 seconds at a combined speed of 108 km/hr. Verify the lengths. Solution: Combined speed = 30 m/s, distance in 8 s = 240 m = sum of both lengths, so each = 120 m. Consistent.

Problem 24. A train at 60 km/hr crosses a tunnel of length equal to the train in 24 seconds. Find the train length. Solution: Speed = 50/3 m/s, total distance = (50/3) × 24 = 400 m = 2 × length, so length = 200 m.

Section C: Boats and Streams (Problems 25-32)

Problem 25. A boat goes 20 km downstream in 2 hours and 12 km upstream in 2 hours. Find boat speed in still water. Solution: Downstream = 10, upstream = 6, still water = (10 + 6)/2 = 8 km/hr.

Problem 26. Using Problem 25 data, find the stream speed. Solution: Stream = (10 - 6)/2 = 2 km/hr.

Problem 27. A boat's speed in still water is 12 km/hr and the stream is 3 km/hr. Find downstream and upstream speeds. Solution: Downstream = 15 km/hr, upstream = 9 km/hr.

Problem 28. A boat covers 36 km downstream in 3 hours. If the stream is 2 km/hr, find the boat's still-water speed. Solution: Downstream speed = 12 km/hr = boat + 2, so boat = 10 km/hr.

Problem 29. A man rows 15 km upstream in 3 hours and 21 km downstream in 3 hours. Find boat speed in still water. Solution: Upstream = 5, downstream = 7, still water = (5 + 7)/2 = 6 km/hr.

Problem 30. A boat rows 24 km downstream in 3 hours and 24 km upstream in 6 hours. Find the stream speed. Solution: Downstream = 24/3 = 8 km/hr, upstream = 24/6 = 4 km/hr. Stream = (8 - 4)/2 = 2 km/hr.

Problem 31. A boat goes 30 km downstream and returns the same 30 km, with downstream speed 10 km/hr and upstream speed 6 km/hr. Find the total time. Solution: 30/10 + 30/6 = 3 + 5 = 8 hours.

Problem 32. A boat travels 16 km upstream in 4 hours. The stream is 1 km/hr. Find the boat's still-water speed. Solution: Upstream speed = 16/4 = 4 km/hr = boat - 1, so boat = 5 km/hr.

Section D: Average Speed (Problems 33-42)

Problem 33. A car covers half a journey at 40 km/hr and half at 60 km/hr. Find average speed. Solution: 2 × 40 × 60 / (40 + 60) = 4800/100 = 48 km/hr.

Problem 34. A man goes at 30 km/hr and returns at 45 km/hr. Find average speed. Solution: 2 × 30 × 45 / (30 + 45) = 2700/75 = 36 km/hr.

Problem 35. A train runs 60 km at 30 km/hr and 60 km at 20 km/hr. Find average speed. Solution: 2 × 30 × 20 / (30 + 20) = 1200/50 = 24 km/hr.

Problem 36. A cyclist rides for 2 hours at 12 km/hr and 3 hours at 18 km/hr. Find average speed. Solution: Total distance = 24 + 54 = 78 km, total time = 5 hours, average = 78/5 = 15.6 km/hr.

Problem 37. A bus covers a route at 50 km/hr and returns at 50 km/hr. Find average speed. Solution: When both speeds are equal, the average equals that speed: 50 km/hr.

Problem 38. A car covers one-third of a distance at 20 km/hr and the rest at 30 km/hr. Find average speed for the whole. Solution: Take distance 60 km. First 20 km at 20 = 1 hour, next 40 km at 30 = 1.33 hours, total 2.33 hours, average = 60/2.33 = 25.7 km/hr.

Problem 39. A man walks to work at 5 km/hr and cycles back at 15 km/hr. Find average speed. Solution: 2 × 5 × 15 / (5 + 15) = 150/20 = 7.5 km/hr.

Problem 40. A train covers 100 km at 50 km/hr and 150 km at 75 km/hr. Find average speed. Solution: Time = 100/50 + 150/75 = 2 + 2 = 4 hours, total distance = 250 km, average = 250/4 = 62.5 km/hr.

Problem 41. A car travels at 60 km/hr for the first half of the time and 40 km/hr for the second half. Find average speed. Solution: For equal time the average is the simple mean: (60 + 40)/2 = 50 km/hr.

Problem 42. A man covers 30 km at 10 km/hr and 30 km at 6 km/hr. Find average speed. Solution: 2 × 10 × 6 / (10 + 6) = 120/16 = 7.5 km/hr.

Key Takeaways

Candidates report that the single most common error in this topic is using the simple average of two speeds when the distances, not the times, are equal. Internalize the 2ab over (a + b) formula and convert units before computing, and most time-speed-distance questions become routine.

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Frequently Asked Questions

What are the must-know time-speed-distance formulas?

The core formula is distance equals speed times time. From it you derive speed equals distance over time and time equals distance over speed. For trains, add the lengths when crossing; for boats, downstream speed is boat plus stream and upstream is boat minus stream. For average speed over equal distances, use twice the product over the sum of the two speeds.

How do I convert between km/hr and m/s?

Multiply km/hr by 5/18 to get m/s, and multiply m/s by 18/5 to get km/hr. Candidates report that memorizing these two conversions saves time on every train and speed question, since the units must match before you compute.

Why is average speed not the simple average of two speeds?

Because you spend more time at the slower speed, the time-weighted average is lower than the simple mean. For equal distances at speeds a and b, the correct average is 2ab over (a plus b). Using the simple average is the most common error in this topic.