Question

The number of six digit numbers, all digits of which are odd, is __________.

Answer 1

For a six-digits number; _ _ _ _ _ possible options of digit are 1, 3, 5, 7, 9
Since each place has all 5 options available
∴ number of six digit numbers, all digit of which are odd is
5 × 5 × 5 × 5 × 5 × 5
= 56