If digits are allowed to be used more than once, you can form
4*5*3 = 60 different numbers.
There are 4 non-zero digits for the leading digit, and 3 odd digits for the least-significant digit. The middle digit can be any of the five digits.
If each digit is only used once, there are 3 digits for the least significant, 4 digits for the middle digit, and a different number of digits available for the most significant, depending on whether the middle digit is zero.
3*1*3 + 3*3*2 = 27 different numbers 301, 501, 801, 103, 503, 803, 105, 305, 805, 531, 831, 351, 851, 381, 581,
513, 813, 153, 853, 183, 583, 315, 815, 135, 835, 185, 385
4*5*3 = 60 different numbers.
There are 4 non-zero digits for the leading digit, and 3 odd digits for the least-significant digit. The middle digit can be any of the five digits.
If each digit is only used once, there are 3 digits for the least significant, 4 digits for the middle digit, and a different number of digits available for the most significant, depending on whether the middle digit is zero.
3*1*3 + 3*3*2 = 27 different numbers 301, 501, 801, 103, 503, 803, 105, 305, 805, 531, 831, 351, 851, 381, 581,
513, 813, 153, 853, 183, 583, 315, 815, 135, 835, 185, 385
