Harshit Singh
Last Activity: 4 Years ago
Dear Student
Let us say,
the average speed of passenger train = x km/h.
Average speed of express train = (x + 11) km/h
Given,
time taken by the express train to cover 132 km is 1 hour less than the passenger train to cover the same distance.
Therefore,
(132/x) – (132/(x+11)) = 1
132(x+11-x)/(x(x+11)) = 1
132 × 11 /(x(x+11)) = 1
⇒ 132 × 11 = x(x + 11)
⇒ x^2 + 11x - 1452 = 0
⇒ x^2 + 44x -33x -1452 = 0
⇒ x(x + 44) -33(x + 44) = 0
⇒ (x + 44)(x - 33) = 0
⇒ x = - 44, 33
As we know, Speed cannot be negative.
Therefore, the speed of the passenger train will be 33 km/h and thus, the speed of the express train will be 33 + 11 = 44 km/h.
Thanks