a padlock has a four - digit code that includes digits from 0 to 9, inclusive. what is the probability that…

a padlock has a four - digit code that includes digits from 0 to 9, inclusive. what is the probability that the code does not consist of all odd digits if the same digit is not used more than once in the code?\n120 out of 5,040\n120 out of 3,024\n2,904 out of 3,024\n4,920 out of 5,040
Answer
Answer:
D. 4,920 out of 5,040
Explanation:
Step1: Calculate total number of four - digit codes
The number of permutations of (n) distinct objects taken (r) at a time is (P(n,r)=\frac{n!}{(n - r)!}). Here (n = 10) (digits from 0 - 9) and (r=4), so (P(10,4)=\frac{10!}{(10 - 4)!}=\frac{10!}{6!}=10\times9\times8\times7 = 5040).
Step2: Calculate number of four - digit codes with all odd digits
There are 5 odd digits (1, 3, 5, 7, 9). Using the permutation formula with (n = 5) and (r = 4), we have (P(5,4)=\frac{5!}{(5 - 4)!}=\frac{5!}{1!}=5\times4\times3\times2=120).
Step3: Calculate number of four - digit codes that are not all odd
The number of four - digit codes that are not all odd is (5040-120 = 4920).
Step4: Determine the probability
The probability that the code does not consist of all odd digits is (\frac{4920}{5040}), which means 4,920 out of 5,040.