SOLUTION: Consider the integers from 1,000 to 9,999 which have only odd digits. a. How many of these have all different digits? b. How many have odd digits with possible digit repetitions?

Question 1199967: Consider the integers from 1,000 to 9,999 which have only odd digits.
a. How many of these have all different digits?
b. How many have odd digits with possible digit repetitions?
Answer by ikleyn(52778) (Show Source): You can put this solution on YOUR website!
.
Consider the integers from 1,000 to 9,999 which have only odd digits.
a. How many of these have all different digits?
b. How many

are there odd numbers with possible digit repetitions?
~~~~~~~~~~~~~~~~

So, there are 5 digits in use : 1, 3, 5, 7, and 9.

(a)  There are  5*4*3*2 = 120  different numbers, as described.     ANSWER


(b)  There are  5*5*5*5 =  = 625  different numbers, as described.          ANSWER

Solved.

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