# PERMUTATION & COMBINATION | IIT JEE CONCEPTS | Part 6 | JEE Advanced 2008 | The Box Method - Videos

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In this video, we will learn an important concept of arrangement – Arrange n objects in n places, so that r objects are always consecutive or together – THE BOX METHOD.
We will discuss the concept for different as well as identical objects.

Question Discussed
Consider all possible permutations of the letters of the word ENDEANOEL.
Match the Statements / Expressions in Column I with the Statements / Expressions in Column II and indicate your answer by darkening the appropriate bubbles in the 4 × 4 matrix given in the ORS.
Column I
(A) The number of permutations containing the word ENDEA is
(B) The number of permutations in which the letter E occurs in the first and the last positions is
(C) The number of permutations in which none of the letters D, L, N occurs in the last five positions is
(D) The number of permutations in which the letters A, E, O occur only in odd positions is
Column II
(p) 5!
(q) 2 × 5!
(r) 7 × 5!
(s) 21 × 5!
Answer: (A) → (p), (B) → (s), (C) → (q), (D) → (q)

TRY YOURSELF Questions
Find the number of arrangements of the letters of the word INDEPENDENCE. In how many of these arrangements
(i) do the words begin with I and end in P (ii) do all the vowels occur together
(iii) Order of vowels is not changed (iv) there are 5 letters between I and P
(i) 12600 (ii) 16800 (iii) 332640 (iv) 151200

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