retagged by
618 views
0 votes
0 votes

A train overtakes two persons who are walking in the same direction in which the train is going, at the rate of $2$ kmph and $4$ kmph and passes them completely in $9$ and $10$ seconds respectively. The length of the train(in metres) is:

  1. $45$
  2. $54$
  3. $50$
  4. $72$
retagged by

1 Answer

0 votes
0 votes

Answer is C

Let length of train be x and speed of the train be y

Case 1 – Person A  → S = $2*\frac{5}{18}m/sec$      t = 9 sec

Case 2 – Person B  → S = $4*\frac{5}{18}m/sec$      t = 10 sec

Dist in Case 1 →  $\frac{x}{y-\frac{10}{18}}=9$   →  x = 9y – 5   -----(1) 

Dist in Case 2 →  $\frac{x}{y-\frac{10}{9}}=10$   →  x = 10y – $\frac{100}{9}$   -----(2)

On solving (1) and (2), we will get x = 50 and y = $\frac{55}{9}$ 

Related questions

0 votes
0 votes
1 answer
1
Lakshman Bhaiya asked Apr 1, 2020
745 views
If a train runs at $40$ kmph, it reaches its destination late by $11$ minutes but if it runs at $50$ kmph, it is late by $5$ minutes only. The correct time for the train ...
0 votes
0 votes
1 answer
2
0 votes
0 votes
1 answer
3
1 votes
1 votes
2 answers
5