About This Cheat Sheet

Complete guide to Permutations and Combinations for competitive exams: fundamental principle of counting (addition and multiplication principles), definition of factorial (n!), permutation formula (nPr = n!/(n-r)!), combination formula (nCr = n!/[r!(n-r)!]), relationship between permutations and combinations (nPr = nCr × r!), permutations with repetitions, permutations with identical objects (n!/(p!q!r!)), circular permutations (n-1)!, number of diagonals in polygon using combinations, number of handshakes problems, selection of teams or committees, problems on forming numbers with digits (with or without repetition), problems on arranging letters of a word (with or without vowels together), problems on selection from mixed groups, distribution of identical objects, and shortcut tricks for SSC, Banking, Railway, UPSC, and other government exams.