Question 1080905
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In the 1-st (leftmost) position the digits are 1 or 3 (2 options).

In the next, 2-nd position, the digits are 1, or 3, or 5, or 7, or 9 (5 options).

In the last, 3-rd position, the digits are 1, or 3, or 5, or 7, or 9 (5 options).


In all, there are 2*5*5 = 50 such numbers.
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