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← JEE Main 2026 · 8 Apr · Shift 2
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JEE Main 2026 · 8 Apr · Shift 2, Mathematics question 8

If 26(233(12C2)+255(12C4)+277(12C6)+⋯+21313(12C12))=313−α26\left(\dfrac{2^3}3\left({}^{12}C_2\right)+\dfrac{2^5}5\left({}^{12}C_4\right)+\dfrac{2^7}7\left({}^{12}C_6\right)+\dots+\dfrac{2^{13}}{13}\left({}^{12}C_{12}\right)\right)=3^{13}-\alpha, then α\alpha is equal to :

Choose one option
Answer and worked solution

Official answer: C

Integral form. 2k+1k+1(12k)=∫02(12k)xk dx\dfrac{2^{k+1}}{k+1}\binom{12}k=\displaystyle\int_0^2\binom{12}kx^k\,dx. The even-k terms come from
∫02(1+x)12+(1−x)122 dx=313−1+1+126=313+126.\int_0^2\frac{(1+x)^{12}+(1-x)^{12}}2\,dx=\frac{3^{13}-1+1+1}{26}=\frac{3^{13}+1}{26}.

Remove k = 0. That term is 2, so the bracket is 313+126−2\dfrac{3^{13}+1}{26}-2 and
26(… )=313+1−52=313−51.26(\dots)=3^{13}+1-52=3^{13}-51.

(C)