There are 4 black balls and 1 white ball in a pocket (touch a ball each time and put it back into the pocket), and Xiaohong touched a black ball 4 times, so what is the possibility of touching a white ball for the 5th time
一个口袋里有4个黑球，1个白球(每次摸一个球再放回袋中)，小红摸了4次都是黑球，那么第5次摸到白球的可能性是多少
<gadget id="calculator">4 + 1</gadget>
<output>5</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<result>1/5 = around 0.2</result>