Question

A train travelling at uniform speed for 360km would have taken 48min leass to travel same distance if its speed were 5 km/h more. Find original speed of the Train.

Answer 1

Hey there! 

Let original speed of the train be x km/h.

Time taken at original speed = 360/x hours

Time taken at increased speed = 360/x+5 hours

Now,

$\frac{360}{x} - \frac{360}{x+5} = \frac{48}{60}$

$360 [ \frac{1}{x} - \frac{1}{x+5} ] = \frac{4}{5}$

⇒ x² + 5x – 2250 = 0

⇒ x = 45 or –50

Speed cannot be negative, so -50 is Rejected.

⇒ x = 45 km/h

HOPE IT HELPS ^_^