UPSC Prelims 2003·GS1·science-and-technology·defence

Three flags, each of different colour, are available for a military exercise. Using these flags, different codes can be generated by waving i) Single flag of different colours, or ii) Any two flags in a different sequence of colours, or iii) Three flags in a different sequence of colour The maximum number of codes that can be generated is

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Last updated 23 May 2026, 3:31 pm IST
  1. A6
  2. B9
  3. C15Correct
  4. D18

Explanation

The total number of codes is the sum of all possible combinations for each of the three scenarios provided. 1. Using a single flag: Since there are 3 different colors available, you can generate 3 unique codes. 2. Using two flags in sequence: For the first position, you have 3 color choices. For the second position, you have 2 remaining color choices. Multiplying these gives 3 times 2, which equals 6 codes. 3. Using three flags in sequence: For the first position, you have 3 choices; for the second, 2 choices; and for the third, 1 choice remaining. Multiplying these gives 3 times 2 times 1, which equals 6 codes. To find the maximum number of codes, add the results together: 3 plus 6 plus 6 equals 15. Therefore, the correct option is C.
science-and-technology: Three flags, each of different colour, are available for a military exercise. Using these flags, different codes can be
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