A businessman imported laptops worth Rs 210000, mobile phones worth Rs 100000 and television sets worth Rs 150000. He had to pay import duties at special rates of 10% on laptops, 8% on phones and 5% on television sets. What is the total duty (in Rs) he had to pay on all the items together?

Introduction / Context:
This problem is a straightforward application of percentage calculation on different parts of a total amount. It involves computing percentage duties on separate categories of imported goods and then adding them to get the total duty. It checks basic arithmetic and the ability to handle multiple percentages correctly.

Given Data / Assumptions:

• Value of laptops imported = Rs 210000, duty rate = 10%.
• Value of mobile phones imported = Rs 100000, duty rate = 8%.
• Value of television sets imported = Rs 150000, duty rate = 5%.
• Total duty is the sum of duties on each category.

Concept / Approach:
The duty on an item is calculated as (duty rate / 100) * value of that item. Since different categories have different rates, we calculate each duty separately and then add the results. There is no compounding or successive percentage here, only simple percentage on fixed base values. This is a common type of problem in profit and loss and taxation concepts.

Step-by-Step Solution:
Step 1: Duty on laptops = 10% of 210000 = 0.10 * 210000 = Rs 21000. Step 2: Duty on mobile phones = 8% of 100000 = 0.08 * 100000 = Rs 8000. Step 3: Duty on television sets = 5% of 150000 = 0.05 * 150000 = Rs 7500. Step 4: Total duty = 21000 + 8000 + 7500. Step 5: Total duty = Rs 36500.

Verification / Alternative check:
As a quick check, we can confirm that each percentage is applied to the correct base. Laptops have the highest value and highest duty rate, giving the largest duty component. Adding 21000 and 8000 gives 29000, and 29000 + 7500 gives 36500. The numbers are consistent and easy to verify manually.

Why Other Options Are Wrong:

• 37000: This is slightly higher than the correct total and suggests that one of the individual duties may have been rounded up or miscalculated.
• 37250: This value does not match the sum of any plausible combination of the given percentage duties.
• 37500: This could come from mistakenly applying 10% on all three categories, which would be wrong.
• 36000: This is lower than the correct total, possibly from miscalculating one of the smaller duty components.

Common Pitfalls:
Students may incorrectly apply a single average percentage to the total value, or mix up which rate applies to which category. Others may mistakenly add percentages before applying them. Careful reading and separate calculations for each category help prevent these errors. Using clear intermediate steps is important when dealing with multiple components.

Final Answer:
The businessman had to pay a total import duty of Rs 36500 on all the items combined.