Answer: In first question: Express train takes 12 seconds to overtake the freight train.
In second question: The train travelling 55 mph will cover x + 300 miles.
Step-by-step explanation:
Here, the freight train travels at 30 mph.
And, the express train traveling at 55 mph,
Therefore, The relative speed of both trains = 55 - 30 = 25 mph
But, the relative distance = 300 miles ( according to the question )
Thus, the time after which the express train will take to overtake the freight train = The relative distance / relative speed = 300/25 = 12 hours.
That is, After 12 hours the Express train will overtake the freight train.
In 12 hours, the distance covered by freight train = 12 × 30 = 360 miles
And the distance covered by the Express train = 12 × 55 = 660 miles
The difference between their covered distance in 12 hours = 660 - 360 = 300 miles
But x represents the distance the train traveling 30 mph travels,
Thus, x = 360 miles and x + 300 = 660 miles
⇒ The train travelling 55 mph will cover x + 300 miles.
