Question

A man walks at a speed of \(8\) km/h. After every kilometre, he takes a rest for \(4\) minutes. How much time will he take to cover a distance of \(6\) km?

• A. \(70\) minutes
• B. \(69\) minutes
• C. \(65\) minutes
• D. \(60\) minutes

Hint:

Remember:

• Convert hours into minutes when needed
• Number of rests: \[ \text{Distance in km} - 1 \] if no rest is taken at the destination

Answer 1

The Correct Option is C

Concept: Time taken: \[ \text{Time} = \frac{\text{Distance}}{\text{Speed}} \] Total time includes:

• Walking time
• Rest time

Step 1: Calculate walking time for \(6\) km. Given: \[ \text{Speed} = 8 \text{ km/h} \] Distance: \[ 6 \text{ km} \] Using: \[ \text{Time} = \frac{6}{8} \] \[ = \frac{3}{4}\text{ hour} \] Converting into minutes: \[ \frac{3}{4}\times 60 = 45 \text{ minutes} \]

Step 2: Calculate total rest time. He rests after every kilometre. For \(6\) km journey, rest is taken after: \[ 1,2,3,4,5 \text{ km} \] Thus total rests: \[ 5 \] Each rest: \[ 4 \text{ minutes} \] Total rest time: \[ 5 \times 4 = 20 \text{ minutes} \]

Step 3: Find total time. \[ \text{Total time} = 45 + 20 \] \[ = 65 \text{ minutes} \] Therefore, \[ \boxed{65 \text{ minutes}} \]