Permutations and Combination Flashcards
Simultaneous occurrence of both events in a definite order
Fundamental principle of multiplication
m*n
Occurrence of exactly one of the events
Fundamental principle of addition
m+n
Exponent of prime number in n!
[n/p]+[n/p^2]+[n/p^3]…
No of permutations of ‘n’ distinct things taken at r at a time
nPr
nPr
n!/(n-r)!
FInd the rank of the word “SACHIN”
601st rank
No. of ways in which m+n distinct things can be divided into two groups containing m and n things
(m+n)!/m!n!
No. of straight lines if ‘n’ non-collinear points
nC2
No. of triangles if ‘n’ non-collinear points
nC3
No. of diagonal of a convex polygon if ‘n’ non-collinear points
nC2 - n
No of rectangles in a chessboard if n and m are the horizontal and vertical lines
nC2*mC2
No of ways of selecting none, one,… or n
1
No. of circular permutations of n distinct is given by
n!/n = (n-1)!
Distribution of n distinct things in p persons such that each may receive none, one, or more given by
p^n
MONKEY MASTER PROBLEM
n identical coins to be distributed in p beggars such that they receive none, one or more
Total ways = n+r-1Cr-1
