Select the number from among the given options that can replace the question mark (?) in the following series.
5, 11, 25, 55, 117, 243, ?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is Option 4 i.e 497.
The pattern followed in the given series is:
(5 × 2) + 1 = 11
(11 × 2) + 3 = 25
(25 × 2) + 5 = 55
(55 × 2) + 7 = 117
(117 × 2) + 9 = 243
Similarly,
(243 × 2) + 11 = 497
Hence, the correct answer is 497.