Question:
A one rupee coin is placed on a table. The maximum number of similar one rupee coins which can be placed on the table, around it, with each one of them touching it and only two others is:
A one rupee coin is placed on a table. The maximum number of similar one rupee coins which can be placed on the table, around it, with each one of them touching it and only two others is:
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This is known as the "kissing circle" or "circle packing" problem. Around one circle, max 6 of equal size can touch it and just 2 others.
Updated On: Aug 7, 2025
- 8
- 6
- 10
- 4
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The Correct Option is B
Solution and Explanation
The arrangement requires:
- Each surrounding coin must touch the central coin
- And each coin should touch only 2 other coins (forming a ring)
This is a classic circle-packing scenario.
In 2D, the maximum number of equal-sized circles that can touch another of the same size = 6 (in a circle).
Hence, placing 6 coins in a hexagonal ring around 1 central coin is possible. Each will touch center and its two neighbors.
\[
\boxed{6}
\]
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