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  1. \(4^5\) numbers.

  2. \(4^4\cdot 2\) numbers (choose any digits for the first four digits - then pick either an even or an odd last digit to make the sum even).

  3. We need 3 or more even digits. 3 even digits: \({5 \choose 3}2^3 2^2\text{.}\) 4 even digits: \({5 \choose 4}2^4 2\text{.}\) 5 even digits: \({5 \choose 5}2^5\text{.}\) So all together: \({5 \choose 3}2^3 2^2 + {5 \choose 4}2^4 2 + {5 \choose 5}2^5\) numbers.

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