Multiple choice

The Sangrur Express train is $800$ metres long. It crosses a tunnel in $1$ minute while running at a speed of $78 km/hr$. What is the length of the tunnel?

  1. $260 m$
  2. $440 m$
  3. $500 m$
  4. $352 m$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Speed = 78 km/hr = 78 * 5/18 = 65/3 m/s. Distance = Speed * Time = (65/3) * 60 = 1300 m. Tunnel length = Total distance - Train length = 1300 - 800 = 500 m.

AI explanation

The total distance covered by the train to cross the tunnel is its length plus the tunnel's length, using the formula distance equals speed multiplied by time. Converting the train's speed to meters per second gives 78 multiplied by 5/18, which equals 65/3 m/s. Multiplying this by the crossing time of 60 seconds yields a total distance of 1300 m. Subtracting the train's 800 m length from this total gives a tunnel length of 500 m.

Keep practicing — related questions