JEE MainMathematicsPermutations and CombinationsMCQ+4 / −1
The sum of all the 4-digit distinct numbers that can be formed with the digits 1, 2, 2 and 3 is :
- A26664
- B122664
- C122234
- D22264
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Correct answer: A
- Form all distinct 4-digit numbers using digits
Since the digit is repeated twice, the number of distinct 4-digit numbers is
- Use place value symmetry
In all distinct arrangements of the multiset , each position (thousands, hundreds, tens, units) gets each digit equally often, accounting for repetition properly.
Let us count how many times each digit appears in a fixed position.
- Total distinct numbers
- Total number of positions filled across all numbers
Now:
- Digit appears once in each number, so across all numbers it appears times total.
- Digit appears once in each number, so across all numbers it appears times total.
- Digit appears twice in each number, so across all numbers it appears times total.
By symmetry, these appearances are equally distributed among the 4 places:
- appears times in each place.
- appears times in each place.
- appears times in each place.
So the sum of digits appearing in any one place is
- Compute total sum
Each place contributes:
- thousands place:
- hundreds place:
- tens place:
- units place:
Hence total sum is
- Check options
matches Option A.
Therefore, the required sum is
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