Menu Close

Category: Permutation and Combination

20-students-should-stand-in-5-different-rows-each-row-should-have-at-least-2-students-in-how-many-ways-can-you-arrange-them-an-unsolved-old-question-

Question Number 179948 by mr W last updated on 04/Nov/22 $$\mathrm{20}\:{students}\:{should}\:{stand}\:{in}\:\mathrm{5} \\ $$$${different}\:{rows}.\:{each}\:{row}\:{should}\:{have} \\ $$$${at}\:{least}\:\mathrm{2}\:{students}.\:{in}\:{how}\:{many}\:{ways} \\ $$$${can}\:{you}\:{arrange}\:{them}? \\ $$$$\left({an}\:{unsolved}\:{old}\:{question}\right) \\ $$ Commented by mr W…

in-how-many-ways-can-you-distribute-20-different-books-to-5-students-such-that-each-student-gets-at-least-2-books-

Question Number 179818 by mr W last updated on 02/Nov/22 $${in}\:{how}\:{many}\:{ways}\:{can}\:{you}\:{distribute} \\ $$$$\mathrm{20}\:{different}\:{books}\:{to}\:\mathrm{5}\:{students}\:{such} \\ $$$${that}\:{each}\:{student}\:{gets}\:{at}\:{least}\:\mathrm{2}\:{books}? \\ $$ Answered by a.lgnaoui last updated on 03/Nov/22 $$…

Number-of-distributions-of-12-different-things-be-taken-to-3different-boxes-so-as-1-5-things-in-1st-box-exactly-2-5-things-in-any-one-box-

Question Number 179738 by SLVR last updated on 01/Nov/22 $${Number}\:{of}\:{distributions}\:{of} \\ $$$$\mathrm{12}\:{different}\:{things}\:{be}\:{taken}\:{to} \\ $$$$\mathrm{3}{different}\:{boxes}\:{so}\:{as} \\ $$$$\left.\mathrm{1}\right)\mathrm{5}\:{things}\:{in}\:\mathrm{1}{st}\:{box}\:{exactly} \\ $$$$\left.\mathrm{2}\right)\mathrm{5}\:{things}\:{in}\:{any}\:{one}\:{box}? \\ $$ Answered by SLVR last updated…

20-students-are-numbered-with-the-numbers-from-1-to-20-10-students-are-randomly-selected-what-is-the-probability-that-the-sum-of-their-numbers-is-exactly-100-

Question Number 179699 by mr W last updated on 01/Nov/22 $$\mathrm{20}\:{students}\:{are}\:{numbered}\:{with}\:{the} \\ $$$${numbers}\:{from}\:\mathrm{1}\:{to}\:\mathrm{20}.\:\mathrm{10}\:{students}\:{are} \\ $$$${randomly}\:{selected}.\:{what}\:{is}\:{the} \\ $$$${probability}\:{that}\:{the}\:{sum}\:{of}\:{their} \\ $$$${numbers}\:{is}\:{exactly}\:\mathrm{100}? \\ $$ Commented by Rasheed.Sindhi last…

Number-of-4-digited-numbers-with-distinct-digits-are-divisible-by-9-i-got-516-i-got-confusion-kidly-help-me-

Question Number 179358 by SLVR last updated on 28/Oct/22 $${Number}\:{of}\:\mathrm{4}\:{digited}\:\:{numbers}\: \\ $$$${with}\:{distinct}\:{digits}…{are}\:{divisible} \\ $$$${by}\:\mathrm{9}..{i}\:{got}\:\mathrm{516}…{i}\:{got}\:{confusion} \\ $$$${kidly}\:{help}\:{me} \\ $$ Commented by mr W last updated on…

you-have-2-identical-mathematics-books-2-identical-physics-books-2-identical-chemistry-books-2-identical-biology-books-and-2-geography-books-in-how-many-ways-can-you-compile-these-books-such-that-

Question Number 113710 by mr W last updated on 14/Sep/20 $${you}\:{have}\:\mathrm{2}\:{identical}\:{mathematics} \\ $$$${books},\:\mathrm{2}\:{identical}\:{physics}\:{books},\:\mathrm{2} \\ $$$${identical}\:{chemistry}\:{books},\:\mathrm{2}\:{identical} \\ $$$${biology}\:{books}\:{and}\:\mathrm{2}\:{geography}\:{books}. \\ $$$${in}\:{how}\:{many}\:{ways}\:{can}\:{you}\:{compile} \\ $$$${these}\:{books}\:{such}\:{that}\:{same}\:{books} \\ $$$${are}\:{not}\:{mutually}\:{adjacent}? \\ $$…