Xiaohong helped her mother type a manuscript, first typed (1/4) of this manuscript, and then typed (2/5) of this manuscript. How much of this manuscript is left untyped?
小红帮妈妈打一份稿件，先打了这份稿件的(1/4)，又打了这份稿件的(2/5)．还剩这份稿件的几分之几没打？
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (1/4) - (2/5)</gadget>
<output>7/20 = around 0.35</output>

<result>7/20 = around 0.35</result>