A number is oddastic if all of its digits are odd. For example, 7. 19 and 353 are oddastic. However 16 and 707 are not oddastic since 6 and 0 are even digits How many of the numbers from 100 to 999 are oddastic? Please select only one answer A. 125 B. 154 C. 155 D. 130
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The Deep Dive
To find the number of oddastic numbers from 100 to 999, we can analyze the three digits of a number. In an oddastic number, each digit must be one of the odd numbers: 1, 3, 5, 7, or 9. 1. The hundreds place can be filled with any of the 5 odd digits (1, 3, 5, 7, 9). 2. The tens place can also be filled with any of the 5 odd digits. 3. The units place can also be filled with any of the 5 odd digits. Therefore, the total number of oddastic numbers is calculated as follows: Total = 5 (choices for hundreds) × 5 (choices for tens) × 5 (choices for units) = 5 × 5 × 5 = 125. So, the correct answer is A. 125.