AP EAMCET2006MathematicsPermutation and Combination
Eight different letters of an alphabet are given. Words of four letters from these are formed. The number of such words with at least one letter repeated is :
Options
- A( array l 8 4 array )- ^8 P₄
- B8^4+ ( array l 8 4 array )
- C8^4- ^8 P₄
- D8^4- ( array l 8 4 array )
Correct answer
C. 8^4- ^8 P₄
Step-by-step solution
Total number of words formed by 4 letters given from eight different letters with repetition =8^4 and number of words with no repetition = ^8 P₄ Required number of words =8^4- ^8 P₄