|A) 1260||B) 2520|
|C) 5040||D) 1080|
The number of ways in which the letters of the word RAILINGS can be arranged such that R & S always come together is
Count R & S as only 1 space or letter so that RS or SR can be arranged => 7! x 2!
But in the word RAILINGS, I repeated for 2 times => 7! x 2!/2! = 7! ways = 5040 ways.