Question

What will come at the place of question mark? 1, 3, 7, 15, 31, ?

• A. 62
• B. 63
• C. 64
• D. 65

Answer 1

Answer:

B. 63

Look at the pattern:

• $1 → (1 \times 2 + 1 = 3)$

• $3 → (3 \times 2 + 1 = 7)$

• $7 → (7 \times 2 + 1 = 15)$

• $15 → (15 \times 2 + 1 = 31)$

Continue the same rule:

• $(31 \times 2 + 1 = 63)$

Answer: 63