DSSSB October 2024
Non Nursing Subjects
Hard

A, B and C are in a cycle race of 24,300 meters. A cycles twice as fast as B. C cycles at one-third the speed of B. C completes the race in 45 minutes. Then where was B from the finishing line when A finished the race?

Appeared in: DSSSB October 2024

Explanation

  • The solution starts by calculating C's speed using the given distance (24,300 m) and time (45 min), which is 540 m/min.
  • Using the relative speed information, B's speed is found to be three times C's speed (3 × 540 = 1620 m/min).
  • Similarly, A's speed is twice B's speed (2 × 1620 = 3240 m/min).
  • The time taken for A to finish the race is calculated by dividing the total distance by A's speed (24300 / 3240 = 7.5 minutes).
  • In these 7.5 minutes, the distance B travels is calculated (1620 m/min × 7.5 min = 12,150 m).
  • Finally, B's distance from the finishing line is the total race distance minus the distance B has covered (24,300 m - 12,150 m = 12,150 m).

Why Other Options Were Wrong

  • Option A: This value is incorrect and likely arises from a miscalculation at one of the steps, such as determining the speeds or calculating the final distances.
  • Option C: This is a numerical error. The precise calculation based on the given speeds and times does not yield this result.
  • Option D: This value is incorrect. It does not match the calculated remaining distance for cyclist B when A finishes the race.

Related Visual

Visual explanation — Related Visual
Clinical Relevance
  • Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain This question tests the application of fundamental concepts of speed, distance, and time, involving relative speeds and multi-step calculations as background academic context rather than a clinical decision trigger.
  • This question tests foundational mathematical reasoning and calculation skills.
  • While not a clinical scenario, the ability to perform multi-step calculations is crucial for nurses in tasks like medication dosage calculation, IV drip rate monitoring, and interpreting patient data trends.
  • Accuracy in calculation is a critical patient safety skill, as errors can have serious consequences in a clinical setting.
How to Approach the Question
  • First, identify all the given variables: total distance, time for one person (C), and the relationships between the speeds of all three people (A, B, C).
  • Use the known distance and time for C to calculate C's speed using the formula: Speed = Distance / Time.
  • Use the speed of C and the given ratios to systematically calculate the speeds of B and then A.
  • Once you have A's speed, calculate the time A takes to complete the full race distance.
  • This time is the key. Use this duration to find out how far B traveled in the same amount of time (Distance = Speed of B × Time of A).
  • Finally, subtract the distance B traveled from the total race distance to find B's distance from the finishing line.
Concept Tested & Keywords
  • Concept Tested: This question tests the application of fundamental concepts of speed, distance, and time, involving relative speeds and multi-step calculations.
  • Stem keywords: cycle race, 24,300 meters, twice as fast, one-third the speed, 45 minutes
  • Lead-in keywords: where was B from the finishing line

Question ID

qF7x4VvzmyKBNfo0g2NOn

Practise the full DSSSB October 2024

Attempt every question from this paper in a timed mock, then review the full solution for each one.

More Mathematics Questions

More DSSSB October 2024 Questions