Question

Look at this series: 7, 10, 8, 11, 9, 12, ... What number should come next?

• A.
• B.
• C.
• D.

Hint:

This series can also be viewed as two interleaved sequences: the first is $(7, 8, 9, \dots)$ and the second is $(10, 11, 12, \dots)$, both increasing by 1.

Answer 1

The Correct Option is B

Step 1: Concept
This is an alternating number series where two different mathematical operations are applied in a repeating pattern to find the next term.
Step 2: Analysis
By observing the transitions between consecutive numbers, we can identify a consistent pattern of addition and subtraction: • $7 + 3 = 10$ • $10 - 2 = 8$ • $8 + 3 = 11$ • $11 - 2 = 9$ • $9 + 3 = 12$
Step 3: Conclusion
Following the established pattern of (+3, -2), the next operation after $+3$ must be $-2$.
$12 - 2 = 10$.
Final Answer: (B)