Question

If a train runs at $40$ km/hr, it reaches its destination late by $11$ minutes, but if it runs at $50$ km/hr, it is late by $5$ minutes only. The correct time for the train to complete the journey is

• A. $13$ min
• B. $15$ min
• C. $19$ min
• D. $21$ min

Answer 1

Answer: (C)

$19$ min

Let the correct time for the train to complete the journey is $x$ minuets

Then train cover distance in $x+11$ minuets at speed $40$ km\hr $=\frac{40(x+11)}{60}$km

Then train cover distance in $x+5$ minuets at speed $50$ km\hr $=\frac{50(x+5)}{60}$km

Both are same then $\frac{40(x+11)}{60}$=$\frac{50(x+5)}{60}$

$\therefore 40x+440=50x+250$

$\therefore -10x=-190$

$\therefore x=19$ minutes