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Let, the length of train is x meter and the velocity of the train is v km/hr.

According to first condition,x(v-4.5)518=8.4.............(i) [∵DistanceVelocity=Time]

According to second condition,x(v-5.4)518=8.5............(ii)

From equation (i) x(v-4.5)518=8.4

=x=(v-4.5)×518×8.4 =x=(v-4.5)×4218 =x=7(v-4.5)3 =3x=7v-314.5 =18x=42v-182............(iii) From Equation (ii)x(v-5.4)518=8.5 =x=8.5×518(v-5.4) =18x=42.5v-229.5..........(iv) Subtracting equation (iii) from equation (iv) 18x=42.5v-229.5 18x=42v-1890=0.5v-40.5 =0.5v=40.5 ∴v=40.50.5=81 ∴The velocity of the train is 81kmph. (answer)

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