S₁ and S₂ are two stations which are 195 km apart. A train starts from S₁ at 4:00 pm and moves towards S₂ at the speed of 65 km/h. Another train starts from S₂ at 5:00 pm and moves towards S₁ at the speed of 35 km/h. At what time will the two trains meet?

Correct option is D

Given:

Distance between stations S1 and S2 = 195 km

Speed of Train 1st  (from S1 to S2) = 65 km/h

Speed of Train 2nd  (from S2 to S1) = 35 km/h

Train 1 starts at 4:00 PM and Train 2 starts at 5:00 PM

Concept Used:

The distance covered by Train 1 in 1 hour (before Train 2 starts) = Speed of Train 1st ×Time

Remaining distance = Total distance - Distance covered by Train 1st

Relative speed when two objects move towards each other = Sum of their speeds

Time = Distance / Relative speed

Solution:

Distance covered by Train 1st  by 5:00 PM = 65 km/h × 1 hour = 65 km

Remaining distance between the trains at 5:00 PM = 195 km - 65 km = 130 km

Relative speed = 65 km/h + 35 km/h = 100 km/h

Time taken to meet after 5:00 PM = $$\frac{130 \text{ km}}{100 \text{ km/h}}$$​= 1.3 hours (or 1 hour 18 minutes)

Meeting time = 5:00 PM + 1 hour 18 minutes = 6:18 PM

The two trains will meet at 6:18 PM.

Hence, the correct option is D: 6:18 p.m.