Q.

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.                   [2008]

  Column I   Column II
(A) The number of permutations containing the word ENDEA is (p) 5!
(B) The number of permutations in which the letter E occurs in the first and the last positions is (q) 2 × 5!
(C) The number of permutations in which none of the letters D, L, N occurs in the last five positions is (r) 7 × 5!
(D) The number of permutations in which the letters A, E, O occur only in odd positions is (s) 21 × 5!
1 (A)(q);  (B)(s);  (C)(q);  (D)(p)  
2 (A)(q);  (B)(q);  (C)(s);  (D)(p)  
3 (A)(s);  (B)(q);  (C)(q);  (D)(p)  
4 (A)(p);  (B)(s);  (C)(q);  (D)(q)  

Ans.

(4)

(A) For the permutations containing the word ENDEA we consider 'ENDEA' as single letter. Then we have total ENDEA, N, O, E, L i.e. 5 letters which can be arranged in 5! ways.

      (A)(p)

(B) If E occupies the first and last position, the middle 7 positions can be filled by N, D, E, A, N, O, L in 
      7!2!=7×6×5×4×3=21×120=21×5!  ways.

      (B)(s)

(C) If none of the letters D, L, N occur in the last five positions then we should arrange D, L, N, N at first four positions and rest five i.e. E, E, E, A, O at last five positions. This can be done in 
       4!2!×5!3!=4×3×5!3×2=2×5!  ways.

        (C)(q)

(D) As per question A, E, E, E, O can be arranged at 1st, 3rd, 5th, 7th and 9th positions and rest D, L, N, N at remaining 4 positions. This can be done in 
      5!3!×4!2! ways=2×5! ways.

       (D)(q)