Find wrong number in series: 8, 24, 12, 36, 18, 54, 26

Concept: This is a 'find the wrong number' series. Such series often follow two alternating operations instead of one constant rule. To solve, apply the alternating operations term by term and locate the position where the expected result does not match the given number.

Application: Following the alternating multiply-by-3, divide-by-2 pattern starting from 8:

1. 8 × 3 = 24

2. 24 ÷ 2 = 12

3. 12 × 3 = 36

4. 36 ÷ 2 = 18

5. 18 × 3 = 54

6. 54 ÷ 2 = 27 (expected), but the series gives 26

Cross-check: Every other term in the series (24, 12, 36, 18, 54) exactly matches the alternating multiply-by-3 / divide-by-2 rule when checked both forward and backward, confirming the rule itself is correct — the only mismatch is at the last position.

Result: The wrong number in the series is 26 (the expected value was 27).