Time and distance

Algebra Level 1

A goods train leaves a station at a certain time and at a fixed speed. After 6 hours, an express train leaves the same station and moves in the same direction at a uniform speed of 90 kmph. This train catches up the goods train in 4 hours. Find the speed of the goods train in kmph.

The answer is 36.

2 solutions

Hanif Robbani
Aug 4, 2014

$v1:$ goods train speed

$v2:$ express train speed

$t1:$ goods train travel time

$t2:$ express train travel time

$\boxed{distance = velocity \times time}$

$distance = v1 \times t1 = v2 \times t2$

$v1(6+4) = v2(4)$

$10v1 = 90(4)$

$v1 = 9(4) = \boxed{36}$

Morrie Verzosa
Jun 21, 2014

distance travelled by express train after 4 hrs d=90kph x 4 hrs = 360km

distance travelled by goods train in 6 hrs d1=v x 6 hrs

distance travelled by goods train in 4 hrs d2 = v x 4 hrs

since d=d1+d2 360=6v + 4v 10v=360 v=360/10 v=36kph

Time and distance

The answer is 36.

2 solutions

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