Q.

The number of 4-letter words, with or without meaning, which can be formed using the letters PQRPQRSTUVP, is __________.           [2026]


Ans.

(1422)

P3, Q2, R2, S,T,U,V

Case I: 3 alike, 1 different

C11×C16×4!3!=24

Case II: 2 alike, 2 alike

C23×4!2!2!=18

Case III: 2 alike, 2 different

C13×C26×4!2!=540

Case IV: All 4 different

C47×4!=840

Total words=1422