CBSE BOARD X, asked by neha3969, 1 year ago

A train travels at certain speed a distance of 63 km and then Travels a distance of 72 km at an average speed it taken 3 hours to complete total Jannat is original average​

Answers

Answered by swati2726
7

Let original speed of the train be x km/h. Then time taken to travel 63 km =63/x hours New speed =(x+6) hours according to the question.

63 upon x + 72 upon x+6 =3

63x + 378 + 72x upon x square + 6x=3

135x + 378 =3x square = 18x

3x square - 117x - 378 =0

x square - 39x -126 =0 (x-42)(x+3)=0 x=-3 or x=42 as the speed can not be negative, x=42 Thus the average speed of the train 42 km/hr.

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