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Question

If 2 is added to each odd digit and 1 is subtracted from each even digit in the number 2741586, how many digits will appear more than once in the new number thus formed?

This question was previously asked in
RRB ALP 2025 CBT 2 Wiremen Question Paper (28-Jul-2026) (Shift 2)
The correct answer is
Two

Number Transformation Process

The task involves modifying the digits of the number \(2741586\) based on whether they are odd or even.

  • Rule for Odd Digits: Add 2.
  • Rule for Even Digits: Subtract 1.

Applying the Digit Rules

Let's process each digit of the number \(2741586\):

  • Digit \(2\) (Even): \(2 - 1 = 1\)
  • Digit \(7\) (Odd): \(7 + 2 = 9\)
  • Digit \(4\) (Even): \(4 - 1 = 3\)
  • Digit \(1\) (Odd): \(1 + 2 = 3\)
  • Digit \(5\) (Odd): \(5 + 2 = 7\)
  • Digit \(8\) (Even): \(8 - 1 = 7\)
  • Digit \(6\) (Even): \(6 - 1 = 5\)

Forming the New Number

Construct the new number using the transformed digits in their original order:

Original Number: \(2 7 4 1 5 8 6\)

New Number: \(1 9 3 3 7 7 5\)

Counting Repeated Digits

Now, we count the occurrences of each digit in the new number \(1933775\) to find digits that appear more than once:

Digits present: \(1, 9, 3, 3, 7, 7, 5\)

  • Digit \(1\) appears 1 time.
  • Digit \(9\) appears 1 time.
  • Digit \(3\) appears 2 times.
  • Digit \(7\) appears 2 times.
  • Digit \(5\) appears 1 time.

The digits that appear more than once are \(3\) and \(7\).

Final Count

There are two distinct digits (\(3\) and \(7\)) that appear more than once in the new number.

Therefore, the correct answer is Two.

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Similar Questions

  1. Select the set that does NOT belong in the following group of sets.

    (2, 14, 16), (6, 30, 36), (5, 35, 40), (3, 21, 24)
  2. Two sets of numbers are given below. In each set of numbers, certain mathematical operation(s) on the first number results in the second number. Similarly, certain mathematical operation(s) on the second number results in the third number and so on. Which of the given options follows the same set of operations as in the given sets? (NOTE: Operations should be performed on the whole numbers, without breaking down the numbers into their constituent digits. E.g. 13 – Operations on 13 such as adding/subtracting/multiplying to 13 can be performed. Breaking down 13 into 1 and 3 and then performing mathematical operations on 1 and 3 is not allowed.) 68 – 136 – 121 – 363; 29 – 58 – 43 – 129
  3. Select the number that does NOT belong in the following group.

    71, 73, 77, 79

  4. (2, 14, 16), (3, 21, 24), (8, 56, 64), (5, 35, 41)
    The set that does NOT belong to the group is:

  5. Select the pair that does NOT belong in the following group.

    (√64,9), (√81,10), (√36,8), (√121,12)

  6. Select the number pair that does NOT belong in the following group.

    (1, 1), (4, 64), (8, 512), (9, 719)

  7. Two sets of numbers are given below. In each set of numbers, certain mathematical operation(s) on the first number result(s) in the second number. Similarly, certain mathematical operation(s) on the second number result(s) in the third number and so on. Which of the given options follows the same set of operations as in the given sets?
    (NOTE: Operations should be performed on the whole numbers, without breaking down the numbers into their constituent digits. E.g. 13 - Operations on 13 such as adding to/subtracting from/multiplying with 13 can be performed. Breaking down 13 into 1 and 3 and then performing mathematical operations on 1 and 3 is not allowed.)
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  8. Two sets of numbers are given below. In each set of numbers, a certain mathematical operation on the first number results in the second number. Similarly, certain mathematical operation on the second number results in the third number and so on. Which of the given options follows the same set of operations as in the given sets?

    (NOTE - A two/three digit number cannot be broken into individual digits for operations e.g. if 37 is followed by 10, the operation cannot be 3+7 as a two digit number cannot be broken into individual digits)

    42 - 45 - 270 - 265
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    (NOTE: Operations should be performed on the whole numbers, without breaking down the numbers into their constituent digits. E.g. 13 – Operations on 13 such as adding to/subtracting from/multiplying with 13 can be performed. Breaking down 13 into 1 and 3 and then performing mathematical operations on 1 and 3 is not allowed.)

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  10. 16 is related to 260 following a certain logic. Following the same logic, 25 is related to 630. To which of the following is 9 related, following the same logic?

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Important Questions from Number Based

  1. In the following question, four number pairs are given. The number on left side of (-) is related to the number of the right side of (-) with some Logic/Rule/Relation. Three are similar on basis of same Logic/Rule/Relation. Select the odd one out from the given alternatives.

  2. Select the set in which the numbers are related in the same way as are the number of the following set.

    (3, 7, 58)

  3. Find the odd number/letters from the given alternatives.

  4. Find the odd number/letters from the given alternatives.

  5. Identify the number which is different from the other.

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