Number series (fill the blank): Alternating +5 and −2 pattern. Given sequence: 28, 33, 31, 36, ?, 39 Identify the missing number following the alternating differences. Choose the correct value.

Q: Number series (fill the blank): Alternating +5 and −2 pattern. Given sequence: 28, 33, 31, 36, ?, 39 Identify the missing number following the alternating differences. Choose the correct value.

Observation Differences alternate: +5, −2, +5, −2, ... Step-by-step calculation 28 → 33: +533 → 31: −231 → 36: +536 → ? : −2 ⇒ ? = 3434 → 39: +5 (checks)

Difficulty: Easy

32
34
38
40

Correct Answer: 34

Explanation:

Observation
Differences alternate: +5, −2, +5, −2, ...

Step-by-step calculation
28 → 33: +533 → 31: −231 → 36: +536 → ? : −2 ⇒ ? = 3434 → 39: +5 (checks)

More Questions from Series Completion

Number series (next square of consecutive odd integers): Continue the pattern. Given sequence: 1, 9, 25, 49, 81, ? Identify the next term as a perfect square of an odd number. Choose the correct value.
Number series (identify the missing square): Odd-number squares sequence. Given sequence: 1, 9, 25, 49, ?, 121 Fill the missing perfect square of an odd integer. Choose the correct value.
Number series (next term): Increasing differences follow n² − 1. Given sequence: 2, 2, 5, 13, 28, ? Use the difference pattern Δ = 1²−1, 2²−1, 3²−1, 4²−1, ... Choose the correct value.
Number series (mixed repeated-difference pattern): find the missing term to complete the sequence. Sequence: 0, 2, 8, 14, ?, 34 Choose the correct value that fits the pattern.
Number series (add consecutive squares): find the next term. Sequence: 1, 5, 14, 30, 55, 91, ? Choose the correct next value.
Arithmetic progression check: determine which option belongs to the series. Series: 10, 17, 24, 31, 38, … (constant difference) Choose the number that appears in this series.
Division-by-successive-integers pattern: identify the missing second term. Sequence: 240, ?, 120, 40, 10, 2 Assume successive divisions by 1, 2, 3, 4, and 5. Choose the correct missing value.
Number series (×n + n rule): compute the next term. Sequence: 2, 3, 8, 27, 112, ? At each step, multiply by the step index and add the same index. Choose the correct next value.
Number series (increasing differences by 11): find the next term. Sequence: 6, 17, 39, 72, ? Compute the missing value using the difference pattern.
Two interleaved sequences: fill the last two terms. Series: 20, 20, 19, 16, 17, 13, 14, 11, ?, ? Identify the odd/even position patterns and compute the missing pair.

Discussion & Comments

No comments yet. Be the first to comment!