The number of 4 letter words (with or without meaning) that can be formed from the eleven letters of the word EXAMINATION is

Step-by-step solution

EXAMINATION 2 N , 2 A , 2 I , E , X , M , T , O Case I : All are different, so 8 P 4 = 8 ! 4 ! = 8 · 7 · 6 · 5 = 1680 Case I I : 2 same and 2 different, so 3 C 1 C 2 7 4 ! 2 ! = 3 · 21 · 12 = 756 Case I I I : 2 same and 2 same, so 3 C 2 4 ! 2 ! 2 ! = 3 · 6 = 18 Total number of words = 1680 + 756 + 18 = 2454