Question

What should come in place of the question mark (?) in the given series? 77 86 104 140 212 ?

• A. 355
• B. 356
• C. 358
• D. 357

Answer 1

Answer:

B. 356

Series:
77, 86, 104, 140, 212, ?

Find differences

$86 - 77 = 9<br>104 - 86 = 18<br>140 - 104 = 36<br>212 - 140 = 72$

Differences:
9, 18, 36, 72

Observe pattern

Each difference is doubling:
$9 \times 2 = 18,; 18 \times 2 = 36,; 36 \times 2 = 72$
Next difference:
$72 \times 2 = 144$

Find next term

$212 + 144 = 356$
Final Answer:

356