How many even three-digit positive integers have the property that exactly two of the integer's digits are even?
+150 Alright, here we go. Lets count out how many there are for odd starting numbers, and then even starting numbers.
For odd: The next two have to be even. So 5 possibilities per row, 5 rows, 25 possibilities for 1,3,5,7,9. So 125 for odd
For even its a bit more complicated. Zero doesn't count because that would be 2 digits. So we start with 2. 50 possibilities for that one. x 4. 200. Answers 325. I know I'm not clear but there's the answer.
325. For all you people that don't want to read.
+150 Alright, here we go. Lets count out how many there are for odd starting numbers, and then even starting numbers.
For odd: The next two have to be even. So 5 possibilities per row, 5 rows, 25 possibilities for 1,3,5,7,9. So 125 for odd
For even its a bit more complicated. Zero doesn't count because that would be 2 digits. So we start with 2. 50 possibilities for that one. x 4. 200. Answers 325. I know I'm not clear but there's the answer.
325. For all you people that don't want to read.
