Verified Solution • 2025–26 Session moderate

QJEEM23Mac8da: JEE Main 2023 Mathematics - Class 11 JEEM23Mac8da Solution: Among the statements : (S1) : is divisible by 8 (S2) : is…

Among the statements :

(S1) : 20232022−199920222023^{2022}-1999^{2022} is divisible by 8

(S2) : 13(13)n−12n−1313(13)^{n}-12 n-13 is divisible by 144 for infinitely many n∈Nn \in \mathbb{N}

Multiple Choice Options

  • A both (S1) and (S2) are incorrect
  • B only (S1) is correct
  • C only (S2) is correct
  • D both (S1) and (S2) are correct

Step-by-Step Verified Solution

We have, S1S_1 : (2023)2022−(1999)2022(2023)^{2022}-(1999)^{2022}

amp;=(1999+24)2022−(1999)2022=2022C0(1999)2022(24)0amp;+2022C1(1999)2021(24)1+2022C2(1999)2020(24)2amp;+…−(1999)2022amp;=2022C1(1999)2021(24)+2022C2(1999)2022(24)2amp;=24(2022C1(1999)2021+2022C2(1999)2022(24)+…+…)amp;⇒S1 is divisible by 24\begin{aligned}& =(1999+24)^{2022}-(1999)^{2022}={ }^{2022} C_0(1999)^{2022}(24)^0 \\\\& +{ }^{2022} C_1(1999)^{2021}(24)^1+{ }^{2022} C_2(1999)^{2020}(24)^2 \\\\& +\ldots-(1999)^{2022} \\\\& ={ }^{2022} C_1(1999)^{2021}(24)+{ }^{2022} C_2(1999)^{2022}(24)^2 \\\\& =24\left({ }^{2022} C_1(1999)^{2021}+{ }^{2022} C_2(1999)^{2022}(24)+\ldots+\ldots\right) \\\\& \Rightarrow S_1 \text { is divisible by } 24\end{aligned}

amp; Now, S2:13(13)n−12n−13amp; Here, 13n=(1+12)namp;=1+nC112+nC2(12)2+nC3(12)3amp;∴S2:amp;13(1+nC1(12)+nC2(12)2+nC3(12)3+…)−12n−13=amp;13+156n+13(nC2(12)2+nC3(12)3+…)−12n−13=amp;144×13(nC2+nC3(12)+…)\begin{aligned}& \text { Now, } S_2: 13(13)^n-12 n-13 \\\\& \text { Here, } 13^n=(1+12)^n \\\\& \quad=1+{ }^n C_1 12+{ }^n C_2(12)^2+{ }^n C_3(12)^3 \\\\& \begin{aligned}\therefore S_2: & 13\left(1+{ }^n C_1(12)+{ }^n C_2(12)^2+{ }^n C_3(12)^3+\ldots\right)-12 n-13 \\\\\quad= & 13+156 n+13\left({ }^n C_2(12)^2+{ }^n C_3(12)^3+\ldots\right)-12 n-13 \\\\\quad= & 144 \times 13\left({ }^n C_2+{ }^n C_3(12)+\ldots\right)\end{aligned}\end{aligned}

⇒S2\Rightarrow S_2 is divisible by 144 for infinitely many n∈Nn \in N

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