Number series – alternating +12, −24, +36, −48, … (magnitudes +12 each time): 620, 632, 608, 644, 596, ?
Verbal Reasoning
Number Series
Difficulty: Easy
Choose an option
Answer
Correct Answer: 656
Explanation
Introduction / Context:An alternating add/subtract pattern with steadily growing magnitudes is a staple in number-series questions. The size of the adjustment increases by a fixed amount each time.
Given Data / Assumptions:
- 620 → 632 (+12)
- 632 → 608 (−24)
- 608 → 644 (+36)
- 644 → 596 (−48)
Concept / Approach:Magnitudes follow 12, 24, 36, 48 → next is 60; signs alternate +, −, +, −, so the next step is +60.
Step-by-Step Solution:
Next term = 596 + 60 = 656.Verification / Alternative check:Continuing would be −72 afterward, maintaining the +12 ladder and sign alternation.
Why Other Options Are Wrong:
646/+50, 556/−40, 536/−60 do not match the required +60 step.Common Pitfalls:Missing the alternating signs and focusing only on magnitudes.
Final Answer:656