If x = _ 2^2 2 + _ 2^3 2^2 + _ 2^4 2^3 + + _ 2^ n+1 2^n, then

JEE Main Mathematics question

If , then

Answer: (B)

The -th term is for ; their product telescopes: . By AMGM on these terms, , i.e. \ge$

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Question ID VK-013080