TCS
Company
Numerical Ability
Permutation and Combination
in how many ways can letters of the english alphabet be arranged so that there are 7 letters between A and B, no letter being repeated.
1) 24P7 * 2 * 18!
2) 36 * 24!
3) 24P7 * 2 * 20!
4) 18 * 24!
Read Solution (Total 6)
-
- A-------B or B-------A => 2 WAYS
from rest 24 letters, 7 can be arranged in 24P7 = 24! ways
also position of A-------B can be 1-------9, 2--------10, ..., 18-------26 => 18 ways
total no. of ways = 24P7 * 2 * 18 - 10 years agoHelpfull: Yes(48) No(9)
- answer 36*24! as a and b are arranged according to condition in 36 ways ,,remaining 24 in 24! ways
- 10 years agoHelpfull: Yes(9) No(5)
- There are P (24, 7) ways to arrange the 7 letters between a and b, 2 ways to place a and b, and then 18! ways to arrange any 9-letter word treated as one unit along with the remaining 17 letters. The total is P (24, 7) (18!) (2).
- 10 years agoHelpfull: Yes(2) No(1)
- A&B can be arranged in places: 1,9 2,10 3,11..........18,26 or 9,1 10,2 11,3........26,18 in 36ways
remaining 24 letters to be arranged in 24 places which is 24P24 ways 24!
total no of ways =24!*36 ways
option:2 - 9 years agoHelpfull: Yes(2) No(2)
- according to me both the options 1and 2 are correct
explaination-
see solutions of saket and rakesh - 8 years agoHelpfull: Yes(0) No(0)
- Value of option 1 and 2 are same
- 8 years agoHelpfull: Yes(0) No(0)
TCS Other Question