Question

Two trains start from $P$ and $Q$ respectively and travel towards each other at a speed of $50$ km/hr and $40$ km/hr respectively. By the time they meet the first train has travelled $100$ km more than second. The distance between $P$ and $Q$ is:

• A. $500$ km
• B. $630$ km
• C. $660$ km
• D. $900$ km

Answer 1

Answer: (D)

$900$ km

At the time of meeting, let the distance travelled by Q, the second train be $x$ km

Then, distance covered by first train $=(x+100)$km

Thus,

$\frac{x}{40}=\frac{x+100}{50}$

$=>5x=4x+400$

$=>x=400$
Thus, distance between P and Q $=(x+x+100)=(400+400+100)=900km$