Two trains start at the same time at 16 km/hr and 21 km/hr one train has travelled 60 km more than the other the distance between is

Options

A. 445 km
B. 444 km
C. 440 km
D. 450km

Answer

To solve the problem, we need to find the distance between two trains that started at the same time, traveling at different speeds, with one train having traveled 60 km more than the other.

### Step-by-Step Solution:

1. **Identify the Speeds of the Trains:**
- Train A travels at 16 km/hr.
- Train B travels at 21 km/hr.

2. **Determine the Relative Speed:**
- The relative speed between the two trains is the difference in their speeds:
\[ \text{Relative Speed} = 21 \text{ km/hr} - 16 \text{ km/hr} = 5 \text{ km/hr} \]

3. **Calculate the Time Taken for the Distance Difference:**
- We know that one train has traveled 60 km more than the other. To find the time taken for this difference, we can use the formula:
\[ \text{Time} = \frac{\text{Distance}}{\text{Relative Speed}} = \frac{60 \text{ km}}{5 \text{ km/hr}} = 12 \text{ hours} \]

4. **Calculate the Distance Travelled by Each Train:**
- Now, we can calculate the distance traveled by each train in that time.
- Distance traveled by Train A:
\[ \text{Distance by A} = \text{Speed of A} \times \text{Time} = 16 \text{ km/hr} \times 12 \text{ hours} = 192 \text{ km} \]
- Distance traveled by Train B:
\[ \text{Distance by B} = \text{Speed of B} \times \text{Time} = 21 \text{ km/hr} \times 12 \text{ hours} = 252 \text{ km} \]

5. **Calculate the Total Distance Between the Two Trains:**
- The total distance between the two trains is the distance traveled by Train B minus the distance traveled by Train A:
\[ \text{Distance between the trains} = 252 \text{ km} - 192 \text{ km} = 60 \text{ km} \]

6. **Final Calculation of the Distance:**
- Since the question asks for the distance between the two trains when one has traveled 60 km more than the other, the distance between the two trains at that moment is 60 km.

### Conclusion:
The distance between the two trains is **60 km**.