A train of length 1 km is running with speed of 60 km/hr. Train enters in a tunnel of length 1 km. How much time will train take to completely out from tunnel?

Question

Accepted Answer

To determine how much time the train will take to completely exit the tunnel, we need to consider the total distance the train must travel and its speed.

1. **Total Distance to Travel:**
   - The train is 1 km long, and it needs to completely pass through a tunnel that is also 1 km long. Therefore, the total distance the train must travel to completely exit the tunnel is the length of the train plus the length of the tunnel, which is $1 \text{ km} + 1 \text{ km} = 2 \text{ km}$.

2. **Speed of the Train:**
   - The train is traveling at a speed of 60 km/hr.

3. **Time Calculation:**
   - Time is calculated using the formula: 
     $$
     \text{Time} = \frac{\text{Distance}}{\text{Speed}}
     $$
   - Substituting the known values:
     $$
     \text{Time} = \frac{2 \text{ km}}{60 \text{ km/hr}} = \frac{1}{30} \text{ hr}
     $$
   - Converting hours into minutes (since 1 hour = 60 minutes):
     $$
     \frac{1}{30} \text{ hr} \times 60 \text{ minutes/hr} = 2 \text{ minutes}
     $$

Therefore, the train will take 2 minutes to completely exit the tunnel, which supports Option 2 as the correct answer.

**Explanation for Incorrect Options:**

1. **Option 1 (1 minute):**
   - If the train took 1 minute, it would mean it traveled 2 km in 1 minute, which would require a speed of 120 km/hr. Since the train's speed is 60 km/hr, this option is incorrect.

2. **Option 3 (1 hour):**
   - If the train took 1 hour, it would mean it traveled 2 km in 1 hour, which would imply a speed of 2 km/hr. This is far slower than the given speed of 60 km/hr, making this option incorrect.

3. **Option 4 (2 hours):**
   - If the train took 2 hours, it would mean it traveled 2 km in 2 hours, implying a speed of 1 km/hr. This is also much slower than the given speed of 60 km/hr, so this option is incorrect.

In conclusion, the correct answer is Option 2, as the train takes 2 minutes to completely exit the tunnel.