six candidates are called for interview to fill four post in an office assuming that each candidate is fit - Maths - Permutations and Combinations

Question

six candidates are called for interview to fill four post in an
office assuming that each candidate is fit for each post determine
the number of ways which (1) first and second post can be filled
(2) first three post can be filled (3) all the four post can be
filled

Gursheen kaur. · Accepted Answer

Total no of candidates=6 (i) No of ways filing first & second posts = no of permutations of 6 candidates taking 2 at a time $= {{}^{6}P}_{2} = 6 \times 5 = 30$ (ii) No of ways filing first three posts = no of permutations of 6 candidates taking 3 at a time $= {{}^{6}P}_{3} = 6 \times 5 \times 4 = 120$ (iii) No of ways filing all the four posts = no of permutations of 6 candidates taking 4 at a time $= 6 \times 5 \times 4 \times 3 = 360$

six candidates are called for interview to fill four post in an office. assuming that each candidate is fit for each post determine the number of ways which (1) first and second post can be filled . (2) first three post can be filled . (3) all the four post can be filled