Two trains P and Q, having lengths of 300m and 340m respectively, are running towards each other. If P and Q are running at speeds of 35 m/s and 45m/s, respectively, then how long will they take to cross each other?

Correct option is B

Given:

Length of Train P = 300 m

Length of Train Q = 340 m

Speed of Train P = 35 m/s

Speed of Train Q = 45 m/s

Formula used:

Time = $$\frac{Distance}{Speed}$$​​

Solution:

When the trains are running towards each other, the total distance is the sum of their lengths:

Total Distance = 300m+340m = 640m

Since the trains are moving towards each other, their relative speed is the sum of their speeds:

Relative Speed = 35m/s + 45m/s = 80m/s

So, Time = $$\frac{Distance}{Speed}$$​ = $$\frac{640}{80}= 8\ sec$$​​

Thus, the correct answer is (B)