Complete the series and evaluate A ÷ 36: 36, 216, 64.8, 388.8, A, 699.84, 209.952. Rule alternates ×6 and ×0.3 (i.e., ×3/10). Find A and then compute A ÷ 36.

Difficulty: Easy

Correct Answer: 3.24

Explanation:

Introduction / Context:This is a completion-and-evaluation series problem with a clear alternating multiplier pattern.

Given Data / Assumptions:

  • Series: 36, 216, 64.8, 388.8, A, 699.84, 209.952.
  • Rule: ×6, then ×0.3, repeating.

Concept / Approach:Apply the two-step alternation across the entire sequence, fill A, and finally compute the requested ratio.

Step-by-Step Solution:

36 × 6 = 216 ✔216 × 0.3 = 64.8 ✔64.8 × 6 = 388.8 ✔388.8 × 0.3 = A = 116.64 ✔116.64 × 6 = 699.84 ✔699.84 × 0.3 = 209.952 ✔Finally, A ÷ 36 = 116.64 ÷ 36 = 3.24.

Verification / Alternative check:Every adjacent ratio alternates between 6 and 0.3, confirming the correctness of A and the final division.

Why Other Options Are Wrong:0.324 and 6.139 are scale/rounding distractors; the exact arithmetic yields 3.24.

Common Pitfalls:Confusing ×0.3 with ÷3; note ×0.3 equals ÷(10/3), not ÷3.

Final Answer:3.24.

Discussion & Comments

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