hi sir, i had a doubt in this question, could you please help-
Octal number system has 8 digits from 0 to 7. How many 4 digit numbers in the octal number system exist such that they are formed using exactly three distinct digits?
here can we do 7*7*6*6 (7, for digits 1-7, and then 7, since we include 0, and so on) =1764 (which is the right answer) but i am not sure if this method is right, as the solution had a lot of cases, so what am i interpreting wrong here?
So, this is not a place to discuss Simcat questions, please note 🙂 I am not sure what logic you have used (could not make sense of the numbers you have taken, as you haven’t accounted for the repeated digit I felt), but if you can justify/prove it then by all means use it.
CAT-holics 
in 2 question in 2 step the set should be 31
which then lead to answer 299
No, since the case (20, 20, 20) has already been accounted for.
regards
J
hi sir, i had a doubt in this question, could you please help-
Octal number system has 8 digits from 0 to 7. How many 4 digit numbers in the octal number system exist such that they are formed using exactly three distinct digits?
here can we do 7*7*6*6 (7, for digits 1-7, and then 7, since we include 0, and so on) =1764 (which is the right answer) but i am not sure if this method is right, as the solution had a lot of cases, so what am i interpreting wrong here?
So, this is not a place to discuss Simcat questions, please note 🙂 I am not sure what logic you have used (could not make sense of the numbers you have taken, as you haven’t accounted for the repeated digit I felt), but if you can justify/prove it then by all means use it.
regards
J