how many 6-digit numbers have only odd digits?

Question

How many 3-digit numbers less than 500 have only odd digits?

Answer 1

(1) 5^6 = 15,625

There are 5 odd digits. A six-digit number can have any of those five digits in each place, which is 5^6 possibilities.

(2) 2*5*5 = 50

The hundreds digit must be 1 or 3 (since the number is under 500), and the remaining two digits can be any odd digit.

Answer 2

There are 5 odd digits 1,3,5,7,9
For 6-digit numbers having only odd digits choose
6 odd digits: 5^6=15,625

For a 3-digit number smaller than 500 choose 1 or 3 for hundreds and two odd digits for tens and units

2*5^2=2*25=50

Answer 3

Hi,

15,625 6-digit numbers have all odd digits.

Each digit can be any of 5 numbers so there are 5 x 5 x 5 x 5 x 5 x 5 = 15,625 numbers with all odd digits

For 3 digit numbers less than 500 with only odd digits, the first digit can only have 2 choices, 1 or 3, so that the number is less than 500. The other 2 digits can be any of the 5 odd digits. This means there are 2 x 5 x 5 = 50 3-digit numbers less than 500 having only odd digits.

I hope that helps!! :-)

Answer 4

Naaah, come on, you can work it out.
how many 1 digit numbers have only odd digits?
how many 2 digit numbers can be made if it's only odd digits?
now even you should be able to work out how mnay for 3 digits, and 4 and 5 and 6...

(clue there's 5 with 1 digit, and 25 for 2 digits)