Explanation:

- Two trains A and B are traveling towards each other from stations P and Q.

- Train A departs at 7 p.m. traveling at 60 km/hr.

- Train B departs at 4 a.m. the next day at 90 km/hr.

- The total distance between P and Q is 800 km.

- Train A travels for 9 hours before Train B starts, covering 540 km (9 hours x 60 km/hr).

- Remaining distance to be covered by both trains is 260 km (800 km - 540 km).

- Combined speed of both trains is 150 km/hr (60 km/hr + 90 km/hr).

- Time for both to meet after Train B starts is approximately 1.73 hours (260 km ÷ 150 km/hr).

- Distance covered by Train B in this time is 156 km (1.73 hours x 90 km/hr).

Correct Answer: Option 3, 156 km

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