How many odd 3-digit whole numbers are there? For example, 203 is acceptable but 023 is not.

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{"content":[{"content":[{"text":"Step 1 (Analyze digit choices):","type":"text","marks":[{"type":"bold"}]},{"text":" We want to construct a 3-digit whole number ","type":"text"},{"attrs":{"latex":"d_1 d_2 d_3"},"type":"math_inline"},{"type":"text","text":" that is odd:"}],"type":"paragraph"},{"attrs":{"start":1},"content":[{"content":[{"content":[{"type":"text","marks":[{"type":"bold"}],"text":"Hundreds place "},{"attrs":{"latex":"d_1"},"type":"math_inline"},{"marks":[{"type":"bold"}],"text":":","type":"text"},{"type":"text","text":" Can be any non-zero digit "},{"attrs":{"latex":"\{1, 2, 3, 4, 5, 6, 7, 8, 9\}"},"type":"math_inline"},{"text":" (9 choices).","type":"text"}],"type":"paragraph"}],"type":"list_item"},{"content":[{"content":[{"marks":[{"type":"bold"}],"text":"Tens place ","type":"text"},{"attrs":{"latex":"d_2"},"type":"math_inline"},{"marks":[{"type":"bold"}],"text":":","type":"text"},{"text":" Can be any digit ","type":"text"},{"attrs":{"latex":"\{0, 1, 2, 3, 4, 5, 6, 7, 8, 9\}"},"type":"math_inline"},{"text":" (10 choices).","type":"text"}],"type":"paragraph"}],"type":"list_item"},{"content":[{"type":"paragraph","content":[{"marks":[{"type":"bold"}],"text":"Units place ","type":"text"},{"attrs":{"latex":"d_3"},"type":"math_inline"},{"marks":[{"type":"bold"}],"text":":","type":"text"},{"text":" Must be odd for the number to be odd. The odd digits are ","type":"text"},{"attrs":{"latex":"\{1, 3, 5, 7, 9\}"},"type":"math_inline"},{"type":"text","text":" (5 choices)."}]}],"type":"list_item"}],"type":"ordered_list"},{"content":[{"marks":[{"type":"bold"}],"text":"Step 2 (Apply product rule):","type":"text"},{"text":" The choices are independent, so:","type":"text"}],"type":"paragraph"},{"attrs":{"latex":"\text{Total odd 3-digit numbers} = 9 \times 10 \times 5 = 450"},"type":"math_block"},{"content":[{"marks":[{"type":"bold"}],"text":"Step 3 (Conclusion):","type":"text"},{"type":"text","text":" There are exactly "},{"marks":[{"type":"code"}],"text":"450","type":"text"},{"type":"text","text":" odd 3-digit whole numbers."}],"type":"paragraph"}],"type":"doc"}

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