Week 14 question 5

Hi Team,

We have the following question where the option does not match with the original answer.
From the question we formulate the three sets as

#A- Set of all possible 4 digit number ( first digit is not zero )
#B - Set of all possible 4 digit number containing at least 1 of the digits as 3
#C - Set of all possible 4 digit number does not contain 3 in any one of the digits ( here the first digit
can not be 0 or 3 )

From the above principle we deduce the values as below:

#B=#A-#C

#B=9000-5832 = 3168.

Kindly clarify whether the above approach is correct.

Thanks,
Harshavardhana

Its a pin-code, first digit (or even all the digits can be zero).