Question

Which of the following numbers will replace the question mark (?) in the given series? 8, 9, 20, 63, 256, ?

• A. 1286
• B. 1284
• C. 1285
• D. 1280

Answer 1

Answer:

C. 1285

The number that will replace the question mark (?) in the series is 1285.

The series follows a pattern of multiplying by a consecutive integer and then adding that same integer:

• $8 \times 1 + 1 = \mathbf{9}$

• $9 \times 2 + 2 = \mathbf{20}$

• $20 \times 3 + 3 = \mathbf{63}$

• $63 \times 4 + 4 = \mathbf{256}$

• $256 \times 5 + 5 = \mathbf{1285}$