Question
We call a natural number "odd looking" if all its digits are odd.How many 4-digit odd looking numbers are there?
Answers
Reiny
Each of the 4 places can be filled with any of the 5 odd digits
number of "odd-looking" number
= 5*5*5*5
= 625 , assuming that digits my be repeated
number of "odd-looking" number
= 5*5*5*5
= 625 , assuming that digits my be repeated