The combined cost of 21 pencils and 9 clippers is ₹ 819 (uniform pricing per item). What is the cost of 7 pencils and 3 clippers together?

Introduction: When pricing is linear and uniform per item, any proportional subset of a given combination costs the same proportion of the total. Here, (7 pencils + 3 clippers) is exactly one-third of (21 pencils + 9 clippers).

Given Data / Assumptions:

• 21 pencils + 9 clippers cost ₹ 819 in total.
• Uniform price per pencil and per clipper (no bulk discounts).
• We need cost of 7 pencils + 3 clippers.

Concept / Approach: Note that (7, 3) is exactly one-third of (21, 9). Therefore, cost scales by 1/3.

Step-by-Step Solution:

Verification / Alternative check: Let pencil = p, clipper = c. Then 21p + 9c = 819. Divide by 3: 7p + 3c = 273. Same result.

Why Other Options Are Wrong: Other figures do not maintain the linear proportionality to the original combination cost.

Common Pitfalls: Attempting to find individual prices unnecessarily; proportional reasoning suffices.

Final Answer: ₹ 273