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There-are-4-identical-mathematics-books-2-identic-physics-books-and-2-identical-chemistry-books-How-many-ways-to-compile-the-eight-books-on-the-condition-of-the-same-book-are-not-mutually-adjacent




Question Number 101693 by bemath last updated on 04/Jul/20
There are 4 identical mathematics  books, 2 identic physics books  and 2 identical chemistry books  . How many ways to compile   the eight books on the condition  of the same book are not mutually  adjacent?
Thereare4identicalmathematicsbooks,2identicphysicsbooksand2identicalchemistrybooks.Howmanywaystocompiletheeightbooksontheconditionofthesamebookarenotmutuallyadjacent?
Commented by bobhans last updated on 04/Jul/20
MPMPMCMC, MPMCMPMC, MPMCMCMP, MCMPMPMC, MCMPMCMP, MCMCMPMP, PMPMCMCM, PMCMPMCM, PMCMCMPM, CMPMPMCM, CMPMCMPM, CMCMPMPM, MPMCMPCM, MPMCMCPM, MCMPMPCM, MCMPMCPM, MPMPCMCM, MPMCPMCM, MCMPCMPM, MCMCPMPM, MPCMPMCM, MCPMPMCM, MPCMCMPM, MCPMCMPM
Commented by bemath last updated on 04/Jul/20
what the formula?
whattheformula?
Answered by bobhans last updated on 04/Jul/20
24 ways
24ways
Commented by bobhans last updated on 04/Jul/20
M_M_M_M_ ⇔ P_4 ^4  = ((4!)/((4−4)!)) = 24 ★
M_M_M_M_P44=4!(44)!=24
Commented by mr W last updated on 04/Jul/20
can you give some explanation to  the formula sir?
canyougivesomeexplanationtotheformulasir?
Answered by mr W last updated on 04/Jul/20
case 1: XMXMXMXM  ⇒((4!)/(2!2!))=6  case 2: MXMXMXMX  ⇒((4!)/(2!2!))=6  case 3: MXYMXMXM, MXMXYMXM, MXMXMXYM  ⇒3×2×2=12    totally: 6+6+12=24
case1:XMXMXMXM4!2!2!=6case2:MXMXMXMX4!2!2!=6case3:MXYMXMXM,MXMXYMXM,MXMXMXYM3×2×2=12totally:6+6+12=24
Answered by john santu last updated on 05/Jul/20
If the math books are in position  1/3/5/7 or 2/4/6/8 there are  6 ways to arrange the physics  and the chemistry → 2×6 = 12  but if the math books are in  position 1/3/5/8 or 1/3/6/8   or 1/4/6/8 then there are only  4 way → 3×4 =12  so totally = 24 ways  (JS ⊛)
Ifthemathbooksareinposition1/3/5/7or2/4/6/8thereare6waystoarrangethephysicsandthechemistry2×6=12butifthemathbooksareinposition1/3/5/8or1/3/6/8or1/4/6/8thenthereareonly4way3×4=12sototally=24ways(JS)

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