How many 2-digit numbers can be formed using the digits 0, 1, 3, 5, 7 and 9 if repetitions are allowed.
my work:
3x5x7 1x0x9
answer = 6 digit numbers can be formed. Is this the correct way of solving this question? If not, whats the correct solution to the problem above?
If a two digit number is required, imagine the places below $$--$$
Now the first place has the options - $\{1,3,5,7,9\}$ as it cannot start with a 0 the second place has no restriction, since repetition is allowed
Hence, number of options for first place - 5
Number of options for second place - 6
Total numbers = 5*6 = 30