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If \({ }^n P_4=1680\), then \(n=\)
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2816 Upvotes
Verified Answer
The correct answer is:
8
\(\begin{aligned}
& \text {Since, }{ }^n P_4=1680 \\
& \Rightarrow \quad n(n-1)(n-2)(n-3)=1680 \\
& \Rightarrow \quad n(n-1)(n-2)(n-3)=8 \times 7 \times 6 \times 5 \Rightarrow n=8
\end{aligned}\)
Hence, option (d) is correct.
& \text {Since, }{ }^n P_4=1680 \\
& \Rightarrow \quad n(n-1)(n-2)(n-3)=1680 \\
& \Rightarrow \quad n(n-1)(n-2)(n-3)=8 \times 7 \times 6 \times 5 \Rightarrow n=8
\end{aligned}\)
Hence, option (d) is correct.
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