Question

An express train takes 1 hour less than a passenger train to travel 132 km between Mysore and Bangalore (without taking into consideration the time they stop at intermediate stations). If the average speeds of the express train is 11 km/h more than that of the passenger train, find the average speed of the two trains.
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Answer 1

Answer:

Step-by-step explanation:

Let the speed of passenger train be x km/hour.  Then speed of express train will be x + 11 km/hour

Time taken by the passenger train = 132 over straight x space hours.

Time taken by the express train = fraction numerator 132 over denominator straight x plus 11 end fraction space hours.

According to question

132 over straight x minus fraction numerator 132 over denominator straight x plus 11 end fraction equals 1                      

Thus speed of passenger train is 33 km/hour and that of express train = 44 km/hour.

Answer 2

Given,

speed of express train = x

speed of passenger train=(x+11)

distance = 132 km

Time = distance/speed

⇒ Time taken by express train = 132/x

⇒ Time taken by passenger train=  132/(x+11)

According to the question,

⇒$\bold{\dfrac{132}{x}-\dfrac{132}{x+11} = 1}$

132(x+11)-132x = x(x+11)

132x +1452-132x = x^2 +11x

⇒ x² + 11x-1452 = 0

x² +44x-33x-1452=0

x(x+44) -33(x+44) = 0

(x+44)(x-33) = 0

x = 33 [-44 neglected]

∴ Speed of express train = 33km/hr

∴ speed of passenger train =(x+11) = 44km/hr.