Q. 31

# A train travels 1

Answer :

Let, the distance covered by the train = d km

Speed of the train = s km/hour

And the time taken by the train = t hour

180 = s × t …(1)

180 = (s + 9) × (t – 1) …(2)

From eq.(1) and eq.(2) 180s + 1620 = 189s + s2

s2 + 9s – 1620 = 0

(s – 36)(s + 45) = 0

s = 36 and -45

But, speed of train is neither be negative.

So, speed of train is 36 km/hour.

OR  3x – 8 = 2x2 – 13x + 15

2x2 – 16x + 23 = 0    and So, the roots of the equation are and Rate this question :

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