If a student’s speed is 60 km/h for half the distance and 40 km/h for the other half, the average speed is: MCQ with Answer and Explanation

If a student’s speed is 60 km/h for half the distance and 40 km/h for the other half, the average speed is:
A. 45 km/h
B. 52 km/h
C. 50 km/h
D. 48 km/h
Answer: Option D
Solution (By JKSSB Mock Tests)
Harmonic mean of 60 and 40 = 2/(1/60 + 1/40) = 48 km/h.

Discuss this Question (0)

No comments yet. Be the first to start the discussion!

Practice More Statistics Questions

Question #1
A person travels from A to B at 40 km/h and returns from B to A at 60 km/h. His average speed for the whole journey is:
A. 50 km/h
B. 52 km/h
C. 45 km/h
D. 48 km/h

Correct Answer: Option D


Explanation:
For equal distances, use Harmonic Mean: 2ab/(a+b) = 2(40)(60)/(100) = 4800/100 = 48 km/h.

This question belongs to: Accountancy and Statistics Statistics
Question #2
Which of the following statements about crude birth rate (CBR) is true?
A. CBR is a refined measure of fertility.
B. CBR is affected by the age structure of the population.
C. CBR = (Total births / Total female population) × 1000
D. CBR includes only male births.

Correct Answer: Option B


Explanation:
CBR uses total population, so age composition influences it.

This question belongs to: Accountancy and Statistics Statistics
Question #3
The circular test is satisfied if an index allows comparison of period 2 with period 0 via period 1, i.e., P₀₁ × P₁₂ = P₀₂. Which index commonly fails this test?
A. Chain base index with fixed weights
B. Laspeyres index
C. Fisher's ideal index
D. Simple geometric mean index

Correct Answer: Option B


Explanation:
Laspeyres index uses fixed base-period weights, so P₀₁ × P₁₂ ≠ P₀₂ in general due to weight rigidity, failing the circular test; Fisher's index satisfies it under certain conditions.

This question belongs to: Accountancy and Statistics Statistics