Latest TCS Aptitude Question SOLUTION: In how many ways can the letters of the english alphabet be arranged so that there are seven letter between the letters A and B, and no letter is repeated a. 24P7 * 2 * 18! b. 36 *

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In how many ways can the letters of the english alphabet be arranged so that there are seven letter between the letters A and B, and no letter is repeated
a. 24P7 * 2 * 18! b. 36 * 24!
c. 24P7 * 2 * 20! d. 18 * 24!

Asked In TCS Garima Srivastava (8 years ago)

Unsolved Read Solution (7)

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Read Solution (7) :

Chinkesh Kumar  (8 years ago)

Answer : B. 36*24!
We can fix A and B in two ways with 7 letters in between them. Now 7 letters can be selected and arranged in between A and B in 24P7 ways. Now Consider these 9 letters as a string. So now we have 26 - 9 + 1 = 18 letters
These 18 letters are arranged in 18! ways. So Answer is 2 x 24P7 x 18!
Infact, 2 x 24P7 x 18! = 36 x 24!. So Option B is Correct.

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janvi  (8 years ago)

ans.b 36*24!

Is this solution Helpfull? Yes (7) | No (2)  

sugandhi.A  (8 years ago)

ans 24P7*2*18!

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Vanshikha Gupta  (8 years ago)

ans is B. 36*24!

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Vipul Goel  (8 years ago)

ans is a

we have total 26 alphabets but two are already given so only 24 left so arranging these 24 in 24p7 ways. Now given A and B can also be arranged in two ways and then the remaining 18 can be arranged in 18! ways.

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Saunak Das  (8 years ago)

24p7*2!*18

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kedar narayana  (8 years ago)

24C7 7! 2! 17! 18
select 7 out of 24 (26-2, 2 is for a and b). keep a, b and the selected 7 in a box. arrange the 7 between a and b in 7! ways. you can have a in the beginning and b at end or vice versa. Hence 2! for that. arrange remaining 17 in 17! ways. put the box of a, b and 7 letters at any place b/w the 17 letters in 18 ways.

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