The distance between A and B is 1,223 km. From A, Chaman goes to B with a…
2026
The distance between A and B is 1,223 km. From A, Chaman goes to B with a speed of 77 km/hr and returns to A with a speed of 150 km/hr. Find the average speed of Chaman. (Rounded off to two decimal places)
- A.
96.51 km/hr
- B.
101.76 km/hr
- C.
108.58 km/hr
- D.
96.35 km/hr
Attempted by 30 students.
Show answer & explanation
Correct answer: B
Step 1: Identify the appropriate formula.
When the distance traveled in both directions is equal (a round trip), the average speed is given by the harmonic mean of the two speeds:
Average Speed = (2 × v₁ × v₂) / (v₁ + v₂)
(Note: The given distance of 1,223 km is extra information and is not needed when using this formula).
Step 2: Substitute the values.
Let v₁ = 77 km/hr and v₂ = 150 km/hr.
Average Speed = (2 × 77 × 150) / (77 + 150)
Average Speed = 23,100 / 227
Step 3: Calculate the final value.
23,100 / 227 ≈ 101.7621... km/hr.
Rounding off to two decimal places gives 101.76 km/hr.
Final Answer: Option 2