A train P starts from station X for station Y and another train Q starts from station Y for station X at the same time. After passing each other, P takes 4 hours to reach Y and Q takes 1 hour to reach X. If the average speed of P is 60 km/h, then what is the average speed of Q ?
- A. 72 km/h
- B. 80 km/h
- C. 96 km/h
- D. 120 km/h ✓
Correct Answer: D. 120 km/h
Explanation
Using the formula S_P / S_Q = \sqrt{T_Q / T_P}, we substitute the given values: 60 / S_Q = \sqrt{1 / 4} = 1/2. Therefore, S_Q = 60 * 2 = 120 km/h.
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