There are 4 pencils, 2 ballpoint pens and 1 pencil in the pen box, if you choose one, what is the probability that it is not a ballpoint pen
笔盒里有4支铅笔、2支圆珠笔和1支铅笔，任取一支，不是圆珠笔的可能性为多少
<gadget id="calculator">4 + 1</gadget>
<output>5</output>

<gadget id="calculator">4 + 2 + 1</gadget>
<output>7</output>

<gadget id="calculator">5 / 7</gadget>
<output>5/7 = around 0.714286</output>

<result>5/7 = around 0.714286</result>