A bus covers the first 10 km of its journey at an average speed of 40 km/h and the remaining 45 km at an speed of 60 km/h. The average speed of the bus for its total journey is

Options

A. 52.5 km/h
B. 50 km/h
C. 57.5 km/h
D. 55 km/h

Answer

To find the average speed of the bus for its total journey, we can follow these steps:

### Step 1: Calculate the total distance
The total distance covered by the bus is the sum of the two segments of the journey:
- First segment: 10 km
- Second segment: 45 km

**Total Distance = 10 km + 45 km = 55 km**

### Step 2: Calculate the time taken for each segment
To find the average speed, we need to calculate the time taken for each segment of the journey.

**For the first segment (10 km at 40 km/h):**
- Time = Distance / Speed
- Time = 10 km / 40 km/h = 0.25 hours (or 15 minutes)

**For the second segment (45 km at 60 km/h):**
- Time = Distance / Speed
- Time = 45 km / 60 km/h = 0.75 hours (or 45 minutes)

### Step 3: Calculate the total time taken
Now, we add the time taken for both segments to find the total time:
- Total Time = Time for first segment + Time for second segment
- Total Time = 0.25 hours + 0.75 hours = 1 hour

### Step 4: Calculate the average speed
Now that we have the total distance and total time, we can calculate the average speed:
- Average Speed = Total Distance / Total Time
- Average Speed = 55 km / 1 hour = 55 km/h

### Final Answer:
The average speed of the bus for its total journey is **55 km/h**.

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