Select the number from among the given options that can replace the question mark (?) in the following series.
23, ?, 89, 177, 353, 705
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 45.
Given series: 23, ?, 89, 177, 353, 705
23 × 2 - 1 = 45; 45 × 2 - 1 = 89; 89 × 2 - 1 = 177; 177 × 2 - 1 = 353; 353 × 2 - 1 = 705