Among the five numbers 5, 6, 7, 8, and 9, if you add any two of them, what is the probability that the sum is an even number?
在5、6、7、8、9这五个数中，将其中的任意两个数相加，和是偶数的可能性是多少．
<gadget id="calculator">4 / 10</gadget>
<output>2/5 = around 0.4</output>

<result>2/5 = around 0.4</result>