TCS Question Asked in TCS Open Seesame:
In how many ways can the letters of the English alphabets be arranged so that there are seven letters between the letters A and B, and no letter is repeated?
a)24P7*2*18!
b)24P7*2*20!
c)18*24!
d)36*24!

• first we can arrange 7 letter b/w in 24p7 way
  then A and B can be arrenge in *2 way so total is 24p7*2
  no consider this 9 letter as 1 number so remainin number can be arrange in
  (26-9+1)!
  so ans = 24p7*2*18!
• 10 years agoHelpfull: Yes(32) No(10)
• we can place A and B in 18 places --> 18*2!
  we can arrange 7 letters between A and B 24p7-->24!/17!
  we can arrange remaining letters in 17!
  
  18*2*(24!/17!)*17!
  36*24!
• 10 years agoHelpfull: Yes(30) No(14)
• This question is a classic example of selections and arrangements.
  All the below explanations are right all I am doing is try to keep it in a simpler format.
  Step #1:-We need to first "select" 7 letters out 24 to keep in between A and B.
  This can be done by 24 C7....Combinations
  Step#2:- We have to find out all the possible arrangements of these seven letters.
  which is 7!.
  Hence combining the above two:-
  Total araangements of picking up 7 alphabets and arranging them in 7 places is 24 C 7 * 7!
  Step #3:- Assuming A.....B as a single entity.
  Step #4;- Hence we we consider A..(seven alphabets)...B as a single alphabet therefore we are left with in all remaining 26-7alphabets- A and B=17 alphabets.
  Step#5:- We now have to find out all the possible arrangements of thiese 18 alphabets(17 remaining and the 1 combined), which is 18!.
  Step#6:- Combining all:-
  
  All possible arrangements= Possible arrangements of 18 alphabets(17 alpha+ 1 combined set)*arrangements within the combined set of 7 alphabets*arrangemets of A & B
  =18! * (24 C 7*7!) * 2!
  =18! * (24!/(17!*7!))*7! * 2!
  =18! * 24!/17!*2!
  =18*24!*2!
  =36*24!
• 10 years agoHelpfull: Yes(26) No(2)
• Options a and b are completely same! So thats the answer too! Just calculate guys!
  
  Ans : a) and d)
• 10 years agoHelpfull: Yes(11) No(0)
• a)
  24P7 ways to arrange letters b/w A and B
  *2 for arrangements of A and B.
  18! for permutation of remaining alphabets with these 9 alphabets
• 10 years agoHelpfull: Yes(7) No(11)
• 24p7*18*2*17!=36*24!
• 10 years agoHelpfull: Yes(5) No(0)
• d) answer hai pakkka..
• 10 years agoHelpfull: Yes(3) No(2)
• ans:d>36*24!
• 10 years agoHelpfull: Yes(2) No(3)
• Answer is option D
  
  But am not Getting it exactly Friends
• 10 years agoHelpfull: Yes(1) No(1)
• ans
  (a) and (d)
  24p7*2*18! = 36*24!
• 10 years agoHelpfull: Yes(1) No(0)
• solve a) and d) option value are same :::::: >?????????
• 10 years agoHelpfull: Yes(0) No(0)
• ans would be, 2*18*24!
  
• 9 years agoHelpfull: Yes(0) No(0)
• ways to choose 7 alphabets from 24 alphabets=24c7
  7 alphabets can be arranged in 7! ways
  for each 7! ways there are 17! ways to arrange 17 alphabets and
  A.......B can be placed at 18 places..
  and 2! ways for A.......B and B........A..
  so ans is 24c7*7!*17!*18*2!
• 9 years agoHelpfull: Yes(0) No(0)
• 24c7(since letter a and b cant b chosen so out of 24 leeter chosin 7)*7!(7 leters arng amon demslv)*18!(consider a,b and the 7 in between as one letter and d left (26-9= 17)letters,so total 18letters,dey arng among demslves)
  (a- - - - - - - b)17letters=26 letters,sso..24c7*7!*18!=24!*18
• 9 years agoHelpfull: Yes(0) No(0)