Study Material — 12 PYQs (2023–2023) · Concept Notes · Shortcuts
IBPS RRB PO Speed Distance Time is a frequently tested subtopic — 12 previous year questions from 2023–2023 papers are included below with concept notes, key rules and shortcut tricks.
Two runners start from the same point. Runner A runs at 8 m/s and Runner B runs at 6 m/s. After how many seconds will Runner A be 100 metres ahead of Runner B?
Exam Q 42023Previous Year Pattern
A train 200 metres long crosses a platform 400 metres long in 30 seconds. What is the speed of the train in km/h?
Exam Q 52023Previous Year Pattern
A train travels 240 km in 4 hours. If it increases its speed by 20%, how much distance will it cover in 5 hours at the new speed?
Exam Q 62023Previous Year Pattern
Two runners, A and B, start from the same point. A runs at 12 km/h and B runs at 8 km/h in the same direction. After how many hours will A be exactly 20 km ahead of B?
Exam Q 72023Previous Year Pattern
A car travels from P to Q at 60 km/h and from Q to P at 40 km/h. The total time for the round trip is 10 hours. What is the distance between P and Q?
Exam Q 82023Previous Year Pattern
A boat travels 48 km downstream in 3 hours and 48 km upstream in 6 hours. What is the speed of the boat in still water?
Exam Q 92023Previous Year Pattern
Rajesh cycles from City A to City B at 15 km/h and returns at 10 km/h. If the total journey takes 10 hours, what is the distance between the two cities?
Exam Q 102023Previous Year Pattern
A train travels from Station A to Station B, a distance of 480 km. It covers the first 240 km at 60 km/h and the remaining distance at 80 km/h. A car travels the same route at a constant speed and takes the same total time as the train. What is the speed of the car in km/h?
Exam Q 112023Previous Year Pattern
A boat travels 60 km upstream and 90 km downstream in a total of 12 hours. The speed of the boat in still water is 12.5 km/h. What is the speed of the current in km/h?
Exam Q 122023Previous Year Pattern
A car travels from City X to City Y at an average speed of 80 km/h. On the return journey, due to traffic, the car travels at 60 km/h. If the total time for the round trip is 14 hours, what is the distance between City X and City Y in km?
Concept Notes
Speed Distance Time— Rules & Concept
💡
Core Concept
Read this first — the foundation of the topic
→Core Concept
Speed measures how fast an object moves. Distance is the path covered. Time is the duration taken. These three are linked by a simple relationship that forms the base of all calculations
💡Key Formulas
• Speed = Distance/Time (S = D/T)
• Distance = Speed × Time (D = S × T)
• Time = Distance/Speed (T = D/S)
Unit Conversions (Critical for SSC):
• km/hr to m/s: Multiply by 5/18
• m/s to km/hr: Multiply by 18/5
• 1 km/hr = 5/18 m/s
📊
Exam Patterns
What examiners ask — read before attempting PYQs
⚡Shortcut 1 - Unit Conversion Trick
To convert km/hr to m/s, multiply by 5/18
💡Remember
36 km/hr = 10 m/s (this is a standard conversion to memorize)
Convert to m/s
Speed in m/s = 60 × 5/18 = 300/18 = 16.67 m/s
Answer: 16.67 m/s
Worked Example 2:
A train running at 54 km/hr takes 20 seconds to cross a platform 200m long. Find the length of the train.
1
Convert speed to m/s
54 km/hr = 54 × 5/18 = 15 m/s
2
Find total distance covered
Distance = Speed × Time = 15 × 20 = 300m
3
Find train length
Train length = Total distance - Platform length = 300 - 200 = 100m
Answer: 100 meters
Shortcut 3 - Relative Speed:
• Same direction: Relative speed = |S1 - S2|
• Opposite direction: Relative speed = S1 + S2
Most Common Trap (#1 Mistake):
Students forget unit conversions! SSC deliberately mixes km/hr and m/s in the same question. Always check units in options and convert accordingly. Questions asking for train crossing times usually need m/s, while car journey problems often use km/hr.
Another frequent error is confusing relative motion directions. When two objects move toward each other, add their speeds. When moving in the same direction, subtract speeds.
Time-based problems often trick students with percentage changes in speed
💡Remember
if speed increases by 25%, time decreases by 20% (not 25%). Use the reciprocal relationship carefully.
Practice identifying whether the question asks for train length, crossing time, or platform length. Each requires different approaches but uses the same core formula.
Key Points to Remember
Master formula: Speed = Distance/Time and its variations D = S × T and T = D/S
Unit conversion: km/hr to m/s multiply by 5/18, m/s to km/hr multiply by 18/5
Standard conversion: 36 km/hr = 10 m/s (memorize this)
Relative speed: same direction subtract speeds, opposite direction add speeds
Train problems: Total distance = Train length + Platform/Bridge length
Speed increase by x%: New time = Original time × 100/(100+x)
Speed decrease by x%: New time = Original time × 100/(100-x)
Always check units in answer options before solving
Average speed = Total distance/Total time (not average of individual speeds)
Time and speed are inversely proportional when distance is constant
Exam-Specific Tips
1 km/hr equals exactly 5/18 m/s
36 km/hr equals exactly 10 m/s
72 km/hr equals exactly 20 m/s
Average speed formula: Total distance divided by total time
Relative speed when objects move toward each other: Sum of individual speeds
Relative speed when objects move in same direction: Difference of individual speeds
When speed increases by 20%, time decreases by 16.67%
When speed decreases by 20%, time increases by 25%
60-Second Revision — Speed Distance Time
Formula: Speed = Distance/Time, Distance = Speed × Time, Time = Distance/Speed
Remember: 36 km/hr = 10 m/s for quick conversions
Unit conversion: km/hr to m/s multiply by 5/18
Trap: Always check if answer needs km/hr or m/s units
Relative speed: Add for opposite directions, subtract for same direction