Hi Ilsa

1st case : the two identiical digits are "1"

Now we have two "1"s and need two more digits.

a. Can you find number of ways to get these two digits?

b. Then can you find the number of arrangements that can be made using those 4 digits?

2nd case : the two identiical digits are "2"

Now we have two "2"s and need two more digits.

a. Can you find number of ways to get these two digits?

b. Then can you find the number of arrangements that can be made using those 4 digits?