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MathsJEE Main 28 Jan 2026, Shift 1·Q7·MCQ·Moderate

Permutations & Combinations · Arrangements with repeated digits

Let S={1,2,3,4,5,6,7,8,9}S = \{1, 2, 3, 4, 5, 6, 7, 8, 9\}. Let xx be the number of 9-digit numbers formed using the digits of the set SS such that only one digit is repeated and it is repeated exactly twice. Let yy be the number of 9-digit numbers formed using the digits of the set SS such that only two digits are repeated and each of these is repeated exactly twice. Then,
  1. (1)29x=5y29x = 5y
  2. (2)45x=7y45x = 7y
  3. (3)21x=4y21x = 4y
  4. (4)56x=9y56x = 9y

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See the full 28 Jan 2026, Shift 1 paper