Find the number of ways in which 6 objects out of 8 can be arranged so that two particular objects are :
(a) included (b) excluded (Hint : (a) 6P2 x 6P4 (b) 6P6)
(i) first letter is a vowel (ii) no two vowels are together
(iii) relative position of vowels and consonants remains unchanged?
Solution not provided.
Ans. (i) 2160, Â (ii) 1440, Â (iii) 144
 (i) How many different numbers of 6-digits can be formed with the numbers 3, 5, 7, 8, 2, 6?
(ii) How many of them are divisible by 5?
(ii) no two vowels are together ?
(iii) vowels may occupy odd places ?
(i) exactly three flags can be used for a signal?
(ii) at most three flags are to be used for a signal?
(iii) at least three flags are to be used for a signal?