Answer: 20
Step-by-step explanation:
The number of ways to arrange n things in which a things are identical , b things are identical and so on...... is given by :-
[tex]\dfrac{n!}{a!b!......}[/tex]
Given Word : ERROR
Total letters = 5
Here letter R is repeated 3 times.
Then, the number of unique ways to arrange the letters in the word "ERROR " will be :-
[tex]\dfrac{5!}{3!}=\dfrac{5\times4\times3!}{3!}=20[/tex]
Hence, the number of unique ways to arrange the letters in the word "ERROR "=20
