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If the letters of the word GRACEFUL are arranged in all possible ways and the words are arranged in a dictionary, then find the rank of the word GRACEFUL.

 

Option: 1

23761


Option: 2

6971


Option: 3

3879


Option: 4

23879


Answers (1)

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Given that the word is GRACEFUL. 

The lexicographic order of the letters of the given word is A, C, E, F, G, L, R, U. The words that begin with A will come first in the lexicographic order.

If the letter A is in the first place of the eight-letter word, then the remaining four letters can be arranged in 7!  ways. On proceeding like this

\begin{aligned} & \mathrm{A}(-----)=7 ! \text { ways } \\ & \mathrm{C}(-----)=7 ! \text { ways } \\ & \mathrm{E}(-----)=7 ! \text { ways } \\ & \mathrm{F}(-----)=7 ! \text { ways } \\ & \text { GA }(-----)=6 ! \text { ways } \\ & \text { GC }(-----)=6 ! \text { ways } \\ & \text { GE }(-----)=6 ! \text { ways } \\ & \text { GF }(-----)=6 ! \text { ways } \\ & \text { GL }(-----)=6 ! \text { ways } \\ & \text { GRACEFUL } 0 \text { ! ways } \end{aligned}

So, the rank of the word GRACEFUL is given by,

\begin{aligned} & =7 !+7 !+7 !+7 !+6 !+6 !+6 !+6 !+6 !+0 ! \\ & =(7 \times 6 \times 5 \times 4 \times 3 \times 2 \times 1)+(7 \times 6 \times 5 \times 4 \times 3 \times 2 \times 1)+(7 \times 6 \times 5 \times 4 \times 3 \times 2 \times 1) \\ & +(7 \times 6 \times 5 \times 4 \times 3 \times 2 \times 1)+(6 \times 5 \times 4 \times 3 \times 2 \times 1)+(6 \times 5 \times 4 \times 3 \times 2 \times 1) \\ & +(6 \times 5 \times 4 \times 3 \times 2 \times 1)+(6 \times 5 \times 4 \times 3 \times 2 \times 1)+(6 \times 5 \times 4 \times 3 \times 2 \times 1)+1 \\ & =5040+5040+5040+5040+720+720+720+720+720+1 \\ & =23761 \end{aligned}

Therefore, the rank of the word GRACEFUL is  23761

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