There are 9 playing cards from 1 to 9, including 4 hearts and 5 spades. Put them upside down on the table and draw any one. What is the probability of getting an odd number of cards?
有1-9共9张扑克牌，其中4张红桃、5张黑桃．把它们反扣在桌子上，任摸一张，摸到奇数牌的可能性是多少．
<gadget id="calculator">5 / 9</gadget>
<output>5/9 = around 0.555556</output>

<result>5/9 = around 0.555556</result>