More Questions from Letter and Symbol Series

All letters of the given series are written in reverse order. In that reversed series, what letter is 8th to the right of the 7th from the left? Original series: C E B A C D B C D A C E B E D C A B A D A C E D U B A U B D B U

Verbal Reasoning Letter and Symbol Series Difficulty: Medium
Choose an option
  • A
    A
  • B
    B
  • C
    C
  • D
    D

Answer

Correct Answer: B

Explanation

Introduction / Context:Indexing problems in reversed sequences are common in verbal reasoning. A direct reversal and recount is possible but time-consuming. A position-mapping shortcut avoids rewriting the sequence and reduces errors.

Given Data / Assumptions:

  • Original sequence has 32 letters: C E B A C D B C D A C E B E D C A B A D A C E D U B A U B D B U.
  • Task in reversed series: find the letter 8th to the right of the 7th from the left.
  • Counting is 1-based (7th means index 7, 8th to the right means +8 positions).

Concept / Approach:In the reversed sequence, the element 8 to the right of the 7th from the left is the element at position 7 + 8 = 15 from the left (in the reversed array). The 15th-from-left in the reversed sequence equals the 15th-from-right in the original sequence. If the original has N elements, the k-th from right is at position N - k + 1 from the left.

Step-by-Step Solution:

1) Compute the target index in the reversed sequence: 7 + 8 = 15.2) Map to the original sequence: 15th from left in reversed = 15th from right in original.3) Total N = 32. The 15th from right is at index N - 15 + 1 = 18 from the left in the original.4) Count to the 18th letter in the original sequence: 1 C, 2 E, 3 B, 4 A, 5 C, 6 D, 7 B, 8 C, 9 D, 10 A, 11 C, 12 E, 13 B, 14 E, 15 D, 16 C, 17 A, 18 B.5) The 18th letter is B.

Verification / Alternative check:You can explicitly reverse the sequence and count to the 15th position; it will also be B, confirming the mapping shortcut.

Why Other Options Are Wrong:

  • A, C, D: Each corresponds to different positions; none matches the 18th-from-left in the original (or 15th-from-left in the reversed).

Common Pitfalls:Forgetting that moving 8 to the right after selecting the 7th adds to 15 total, or misapplying the N - k + 1 mapping. Another common mistake is switching to 0-based counting mid-way.

Final Answer:B

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