Correct Answer: Option B: 40 km
To solve this problem, we need to determine the total distance to Mr. Kumar's office. Let's denote the total distance as $D$ kilometers.
     Step 1: Understanding the problem
         ○ Mr. Kumar drives at an average speed of 48 km/h.
         ○ The time taken to cover the first 60% of the distance is 10 minutes more than the time taken to cover the remaining 40% of the distance.
     Step 2: Express the distances
         ○ The first 60% of the distance is $0.6D$.
         ○ The remaining 40% of the distance is $0.4D$.
     Step 3: Calculate the time taken for each part of the journey
         ○ Time taken to cover the first 60% of the distance:
       $$\text{Time}_1 = \frac{0.6D}{48} \text{ hours}$$
         ○ Time taken to cover the remaining 40% of the distance:
       $$\text{Time}_2 = \frac{0.4D}{48} \text{ hours}$$
     Step 4: Set up the equation based on the given condition
         ○ According to the problem, the time for the first 60% is 10 minutes (or $\frac{10}{60} = \frac{1}{6}$ hours) more than the time for the remaining 40%:
       $$\frac{0.6D}{48} = \frac{0.4D}{48} + \frac{1}{6}$$
     Step 5: Solve the equation
         ○ Simplify the equation:
       $$\frac{0.6D}{48} - \frac{0.4D}{48} = \frac{1}{6}$$
         ○ Combine the terms:
       $$\frac{0.2D}{48} = \frac{1}{6}$$
         ○ Multiply both sides by 48 to solve for $D$:
       $$0.2D = 8$$
         ○ Divide by 0.2:
       $$D = \frac{8}{0.2} = 40$$
     Therefore, the total distance to Mr. Kumar's office is 40 km.