Each term = previous x 2 + 1 (3, 7, 15, 31 / 5, 11, 23, 47 ...)

The same question, asked 7 times: 16 Sep 2025 S1*, 17 Sep 2025 S3*, 18 Sep 2025 S2*, 19 Sep 2025 S1*, 21 Sep 2025 S1*, 23 Sep 2025 S1*, 23 Sep 2025 S2. Every wording below, oldest first.

Try each one first, then open its answer.

Question 1
16 Sep 2025 S1
7 $What will come at the place of question mark? 1, 3, 7, 15, 31, ?$
Tap an option to check your answer.
Question 2
17 Sep 2025 S3
24 $Find the next number in the series:3, 7, 15, 31, 63, ?$
Tap an option to check your answer.
Question 3
18 Sep 2025 S2
23 $Find the next number in the series: 10, 21, 43, 87, ?, 351$
Tap an option to check your answer.
Question 4
19 Sep 2025 S1
24 $Find the next number in the series : 2, 5, 11, 23, 47, ?$
Tap an option to check your answer.
Question 5
21 Sep 2025 S1
23 $What should come at the place of question mark? 2, 5, 11, 23, 47, ?$
Tap an option to check your answer.
Question 6
23 Sep 2025 S1
14 $What should come at the place of question mark? : 4, 9, 19, 39, 79, ?$
Tap an option to check your answer.
Question 7
23 Sep 2025 S2
18 $Complete the series. 5, 11, 23, 47, ?$
Tap an option to check your answer.
Question 8
23 Sep 2025 S2
20 $What should come at the place of question mark? : 31, 63, 127, 255, 511, ?$
Tap an option to check your answer.

Each term = previous x 2 + 1 (3, 7, 15, 31 / 5, 11, 23, 47 ...)

Question 1

Question 2

Question 3

Question 4

Question 5

Question 6

Question 7

Question 8