In the following number series, a wrong number is given. Find out the WRONG number.
9, 19, 39, 78, 159, 319
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 78.
Given series: 9, 19, 39, 78, 159, 319
9 × 2 + 1 = 19, 19 × 2 + 1 = 39, 39 × 2 + 1 = 79 ≠ 78, 79 × 2 + 1 =159, 159 × 2 + 1 = 319