What should come in place of the question mark (?) in the following series? 3, 7, 15, 31, 63, ?
Answer
The correct answer is C: 127. Each term is obtained by multiplying the previous term by 2 and adding 1 (3×2+1=7, 7×2+1=15, 15×2+1=31, 31×2+1=63, 63×2+1=127).
A.168
B.576
C.127✓ Correct
D.177
Explanation
Each term is obtained by multiplying the previous term by 2 and adding 1 (3×2+1=7, 7×2+1=15, 15×2+1=31, 31×2+1=63, 63×2+1=127).
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