Which of the following statement(s) is/are wrong? A. A man runs at a speed of…
2025
Which of the following statement(s) is/are wrong?
A. A man runs at a speed of 20 km/hr and covers a distance of 400 m. The time taken by the man to cover 400 m is 8 minutes.
B. A person covers a certain distance at x km/hr and an equal distance at y km/hr. The average speed during the whole journey is (2xy)/(x+y) km/hr.
C. A Cyclist covers a distance of 750 m in 2 minutes. The speed of the cyclist is 18 km/hr.
D. A speed of x km/hr is equal to (5x)/18 m/sec. Choose the most appropriate answer from the options given below:
- A.
A Only
- B.
A and B Only
- C.
A and C Only
- D.
B, C and D Only
Attempted by 16 students.
Show answer & explanation
Correct answer: C
Statement A: Speed = 20 km/hr, Distance = 400 m. Time taken is 72 seconds (1.2 minutes). The statement claims 8 minutes, so A is wrong.
Statement B: The average speed for equal distances at x km/hr and y km/hr is given by 2xy/(x+y). This statement is correct.
Statement C: Distance = 750 m in 2 minutes. Speed is (750/120) * (18/5) = 22.5 km/hr. The statement claims 18 km/hr, so C is wrong.
Statement D: To convert km/hr to m/sec, multiply by 5/18. So x km/hr = (5x)/18 m/sec. This statement is correct.
Conclusion: Statements A and C are the incorrect statements.