Digit-rearrangement difference: Arrange the digits of 92581473 in ascending order to form a new number. What is the difference between the digit that is fourth from the right and the digit that is third from the left in this new arrangement?

Difficulty: Easy

Correct Answer: Two

Explanation:


Introduction / Context:
Ordering digits and picking positional values is a staple reasoning task. Here, you form a strictly ascending sequence, then index from different ends and compute a numeric difference.



Given Data / Assumptions:

  • Original digits: 9, 2, 5, 8, 1, 4, 7, 3.
  • New arrangement: ascending order.
  • Positions requested: 4th from right, 3rd from left.




Concept / Approach:
Ascending order for the digits yields a unique sequence. Convert “k-th from right” to an index from the left if helpful (for an 8-digit number, 4th from right = 5th from left).



Step-by-Step Solution:

Step 1: Sort digits ⇒ 1, 2, 3, 4, 5, 7, 8, 9.Step 2: 4th from right ⇒ position 8 - 4 + 1 = 5th from left ⇒ digit 5.Step 3: 3rd from left ⇒ digit 3.Step 4: Difference ⇒ 5 - 3 = 2.




Verification / Alternative check:
Visual scan from the right: rightmost digits are 9(1st), 8(2nd), 7(3rd), 5(4th) ⇒ still 5. Third from left remains 3.



Why Other Options Are Wrong:

  • One/Three/Four/Zero: Not equal to 2; arise from index miscounts.




Common Pitfalls:
Forgetting that “from right” reverses the direction; mis-sorting (placing 7 before 5), or missing that there are eight digits.



Final Answer:
Two

More Questions from Ranking Test

Discussion & Comments

No comments yet. Be the first to comment!
Join Discussion