1.  A train moves past a telegraph post and a bridge 264 m long in 8 seconds and 20 seconds respectively. What is the speed of the train?
A. 69.5 km/hr
B. 70 km/hr
C. 79 km/hr
D. 79.2 km/hr

Answer: Option D

Explanation:

Let the length of the train be x metres and its speed by y m/sec.

Then, x = 8     =>     x = 8y
y

Now, x + 264 = y
20

=> 8y + 264 = 20y

=> y = 22.

Therefore Speed = 22 m/sec = ( 22 x 18 ( km/hr = 79.2 km/hr.
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