Question
Question: The number of ways in which the letters of the word ARRANGE can be arranged such that both R do not ...
The number of ways in which the letters of the word ARRANGE can be arranged such that both R do not come together is
A
360
B
900
C
1260
D
1620
Answer
1260
Explanation
Solution
The word ARRANGE, has AA, RR, NGE letters, that is two A' s, two R's and N, G, E one each.
∴The total number of arrangements
= 2!2!1!1!1!1!7! = 1260
But, the number of arrangements in which both RR are together as one unit = 2!1!1!1!1!6! = 360.
The number of arrangements in which both RR do not come together = 1260 – 360 = 900.