There are 4 red, white, and yellow balls in the bag, at least how many balls must be taken out of the bag to ensure that there are three colored balls in the bag at the same time.
袋中有红、白、黄三种颜色的小球各4个，至少要从中拿出多少个小球才能保证拿出的球中同时有三种颜色的小球．
<gadget id="calculator">4 * 2</gadget>
<output>8</output>

<gadget id="calculator">8 + 1</gadget>
<output>9</output>

<result>9</result>