Write the 10 numbers from 1 to 10 on 10 identical paper strips, make paper balls and mix them in the box, and take out a piece of paper, what is the probability that there is a prime number written on the paper strip
把1-10这10个数分别写在10张完全相同的纸条上，做成纸团在盒中混合，从中摸出一张纸条，纸条上写有质数的可能性是多少
<gadget id="calculator">4 / 10</gadget>
<output>2/5 = around 0.4</output>

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