Questionbank: Permutation and Probability

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Clue - FInd the number of rearrangements and then focus on the number of digits

Sum of Rearrangements

    Q.27: What is sum of all rearrangements of the 4-digit number 3214?
    1. 29999
    2. 27777
    3. 28888
    4. 29997


  • Correct Answer
    Choice D. 29997

Detailed Solution

Each of the four digits is likely to appear in the units place , but the digit 3 will appear twice as that of 2 and 1.

Therefore, sum of units place = 3*2 +3*1 + 6*3 = 27.

Sum of tens place = 270

Sum of hundreds place = 2700

Sum of thousands place =27000

Sum of all arrangements of 3321 = 29997.

Correct Answer : 29997

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