Linear cost calculation with two item types: Joel purchased 40 notebooks at the rate of ₹18 per notebook and 55 pencils at the rate of ₹8 per pencil. What is the total amount that he paid to the shopkeeper?

Introduction / Context:This is a straightforward linear-cost problem where the total bill equals the sum of (quantity * unit price) across item categories. Such questions test quick arithmetic with money units and attention to rates and counts without mixing them up.

Given Data / Assumptions:

• Notebooks: 40 units at ₹18 each.
• Pencils: 55 units at ₹8 each.
• All prices are per item with no discounts or taxes mentioned; add the two subtotals to get the total payment.

Concept / Approach:Total cost = (quantity_notebooks * price_notebook) + (quantity_pencils * price_pencil). Compute both subtotals precisely and then add them, keeping the currency in ₹ throughout to avoid unit confusion.

Step-by-Step Solution:

Verification / Alternative check:Check by breaking 55 * 8 as (50 * 8) + (5 * 8) = 400 + 40 = 440, then add 720 to get 1,160. Both routes agree, confirming accuracy.

Why Other Options Are Wrong:₹1,165, ₹1,166, and ₹1,161 are near but result from small arithmetic slips; ₹1,150 ignores part of the pencil cost. None matches the exact computed sum of ₹1,160.

Common Pitfalls:Multiplying the wrong quantities and prices, forgetting that the pencil rate is ₹8 (not ₹18), or dropping tens while adding subtotals are frequent small errors in speed tests.

Final Answer:₹1,160