Question

You are given the letters M-A-T-H-I-S-F-U-N. How many unique 4-letter arrangements can be made using those letters?

Answer 1

SEE FIRST PLACE CAN BE FILLED IN 9 WAYS AND SECOND IN 8 WAYS AND THIRD 7 AND FOR FOURTH 6
HENCE REQD. NO OF WAYS IS 9*8*7* (IF REPITITION OF LETTER ARE NOT ALLOWED
IF REPITITION IS ALLOWED THEN IT C IS 9*9*9*9 =