Question

15) All possible 120 permutations of WDSMC are arranged in dictionary order, as if each were an ordinary five - letter word. The last letter of the 86th word in the list is :
(a) W
(b) D
(c) M
(d) C

Answer 1

Answer:

Step-by-step explanation:

Letters in alphabetical order are - C,D,M,S,W

No. of letters starting from C = 4! = 24

No. of letters starting from D = 4! = 24

No. of letters starting from M = 24

No. of letters starting from S = 24

now 97th letter starts from W and 73rd letter starts from S

so 86th letter starts from S

now fix S and C

letters starting from SC = 3! = 6

similarly from SD = 6

now we have reached 84 words

85th word starts from SM and it is SMCDW

so 86th word is SMCWD

Answer 2

Step-by-step explanation:

Answer:

Step-by-step explanation:

Letters in alphabetical order are - C,D,M,S,W

No. of letters starting from C = 4! = 24

No. of letters starting from D = 4! = 24

No. of letters starting from M = 24

No. of letters starting from S = 24

now 97th letter starts from W and 73rd letter starts from S

so 86th letter starts from S

now fix S and C

letters starting from SC = 3! = 6

similarly from SD = 6

now we have reached 84 words

85th word starts from SM and it is SMCDW

so 86th word is SMCWD