Practice Test GeeksUSPS Error Detection Test Practice Test
← All USPS Flashcard Decks

Number Sequence Comparison Flashcards

7 cards from real USPS practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 7 Number Sequence Comparison flashcards as text

  1. A mail handler must verify a 12-digit package ID. Find the error: Original: 420 921 048 375 Copy: 420 921 084 375

    Answer: Segment 3 (048)

    Segment 3 changed from '048' to '084', swapping the second and third digits.

  2. Original: 8001 1008 2002 3003 Copy: 8001 1008 2002 3003 A new clerk flags this as having an error because the numbers look symmetric. The clerk is:

    Answer: Incorrect — the sequences are identical

    The sequences are identical; symmetric-looking numbers are a common distractor on detection tests.

  3. Original route code: 7-3-19-42-88-101 Copy: 7-3-19-42-88-110 What changed?

    Answer: The 6th element had its digits transposed

    The last element '101' became '110', with the last two digits transposed.

  4. Which of the following number pairs contains a transposition error (not a substitution)? A) 5839 / 5930 B) 7264 / 7246 C) 4417 / 4471 D) 3058 / 3508

    Answer: Pairs B, C, and D

    Pairs B ('64'→'46'), C ('17'→'71'), and D ('05'→'50') each swap two digits; Pair A replaces '83' with '93', which is a substitution.

  5. Original: 10203 40506 70809 Copy: 10203 40560 70809 The error is in which group, and which digits were swapped?

    Answer: Group 2 — digits 4 and 5

    In Group 2, the 4th and 5th digits changed from '06' to '60', a transposition of those positions.

  6. A clerk compares two lists of delivery confirmation numbers: List 1: 9400 1109 9922 4455 List 2: 9400 1109 9922 4545 How many digits differ between the two lists?

    Answer: 2 digits

    In the last group, position 3 changed from '5' to '4' and position 4 changed from '5' to '5' — actually '4455' vs '4545' means positions 2 and 3 differ, totaling 2 digits.

  7. Original ZIP+4: 75201-3348 Copy: 75201-3438 Where is the error?

    Answer: In the 2nd and 3rd digits of the 4-digit extension

    The extension '3348' became '3438', swapping the 2nd digit '3' and 3rd digit '4'.