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        <description>Merging man &amp; maths</description>
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            <title>Ch 07: Permutation, Combination and Probability</title>
            <link>https://www.mathcity.org/fsc-part1-ptb/important-questions/ch07-permutation-combination-and-probablity</link>
            <description>Ch 07: Permutation, Combination and Probability

	*  Find $n$ when ${^nC_{12}}={^nC_6}$ --- BISE Gujranwala(2015)
	*  Evaluate  ${^{20}C_{17}}$ without calculator --- BISE Gujranwala(2015)
	*  How many $6-digit$ numbers can be formed from the digits $2,2,3,3,4,4$? How many of them with lie between $400,000$ and $430,000$?  ---$``PLANE&quot;$$^nC_4=^nC_{n-r}$$6-digits$$n^3-n$$6$$n=2,3$$n$$^nP_2=30$$6-dided$$n$$^nC_{12}=^nC_6$$^{n-1}C_r+^{n-1}C_{r-1}=^nC_r$$\frac{a_5}{a_3}=\frac{4}{9}$$a_2=\frac{4}{9}$…</description>
            <author>anonymous@undisclosed.example.com (Anonymous)</author>
            <pubDate>Sun, 07 Feb 2021 16:47:42 +0000</pubDate>
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