(Q). In how many ways batting order of 11 players can be made out of 15 players ?
Sol:- First select then arrange.
11 Players can be selected out of 15 players in ¹⁵C₁₁ ways.
Now these 11 players can be arranged in 11! ways.
Hence total number of ways = ¹⁵C₁₁.11! Answer
(Q). In how many ways 5 distinct volume of chemistry & 7 distinct volume of chemistry books can be arranged on a bookshelf ?
Sol:- Here all 12 articles are different & we are to arrange them.
which can be done in 12! ways Answer
(Q). In how many ways 5 distinct volume of chemistry & 7 distinct volume of botany books can be arranged on a bookshelf such that all the botany books are together ?
Sol:-
∴ total number of ways to arrange =