Xiaohong took the mathematics graduation exam, and spent (1/5) of the total time on filling in the blanks and judgment questions, (1/4) of the total time on multiple choice questions and calculation questions, and (7 /20), how much time he has left to check.
小红参加数学毕业考试，填空题和判断题用了总时间的(1/5)，做选择题和计算题用了总时间的(1/4)，做应用题用了总时间的(7/20)，他还剩下多少时间可以检查．
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">7 / 20</gadget>
<output>7/20 = around 0.35</output>

<gadget id="calculator">1 - (1/5) - (1/4) - (7/20)</gadget>
<output>1/5 = around 0.2</output>

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