Question

An express train takes 1 hr less than a passenger train to travel 132km between mysore and bangalore. If the speed of express train is 11km/hr more than that of the passenger train find average speed of the two trains​

Answer 1

ANSWER:----

1. distance of 132 km is 1 hour less than the passenger train to cover the same distance.
2. Time taken by passenger train = 132/x hr
3. The time taken by the express train = {(132)/x+11} hr
4. {132/(x+11)} = 132/x + 1
5. After taking L.C.M. of 132/x +1 and then solving it we get (132+x)/x.

Now then,

1. {132/(x+11)} = (132+x)/x
2. multiplying, we get
3. 132x = x²+132x+11x+1452
4. x² + 11x - 1452 = 0
5. x² + 44x - 33x - 1452 = 0
6. x(x+44) - 33(x+44) = 0(x+33) (x+44) = 0

• x - 44 or x = 33As the speed cannot be in negative

therefore

x = 33 or the speed

• passenger train = 33 km/hr and the speed is 33 + 11 = 44 km/hr

hope it helps..