A person wants to travel a distance of 50 km by his bicycle. He travels with a speed of 12.5 km/hr. After every 12.5 km, he takes a rest of 20 minutes. How much time will he take to complete the whole distance?

Options

A. 4 hrs 20 min
B. 5 hrs 20 min
C. 5 hrs
D. 6 hrs

Answer

To solve the problem step by step, we will calculate the total time taken by the person to travel 50 km on his bicycle, including the time taken for rest.

### Step 1: Calculate the time taken to travel 50 km without rest
We know that the formula to calculate time is:
\[ \text{Time} = \frac{\text{Distance}}{\text{Speed}} \]
Here, the distance is 50 km and the speed is 12.5 km/hr.

\[ \text{Time} = \frac{50 \text{ km}}{12.5 \text{ km/hr}} = 4 \text{ hours} \]

### Step 2: Determine how many rests the person takes
The person takes a rest after every 12.5 km. We need to find out how many 12.5 km segments are in 50 km.

\[ \text{Number of segments} = \frac{50 \text{ km}}{12.5 \text{ km}} = 4 \]

Since he takes a rest after completing each segment, he will take rests after the first three segments (he does not take a rest after the last segment, as he has reached his destination).

### Step 3: Calculate the total rest time
The person takes a rest of 20 minutes after each of the first three segments. Therefore, the total rest time is:

\[ \text{Total rest time} = 3 \times 20 \text{ minutes} = 60 \text{ minutes} = 1 \text{ hour} \]

### Step 4: Calculate the total time taken
Now, we add the travel time and the rest time together to find the total time taken to complete the journey.

\[ \text{Total time} = \text{Travel time} + \text{Rest time} = 4 \text{ hours} + 1 \text{ hour} = 5 \text{ hours} \]

### Final Answer
The total time taken to complete the whole distance is **5 hours**.

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