A garment factory processes a batch of garments, the ratio of the number of processed pieces to the total number of garments is 2:5, and then 75 pieces are processed, which is exactly (13/20) of this batch of clothes. How many pieces of this batch of clothes are left unprocessed?
服装厂加工一批服装，已加工的件数与衣服总件数之比是2：5，再加工75件，正好完成这批衣服的(13/20)．求这批衣服还剩多少件没有加工？
<gadget id="calculator">13 / 20</gadget>
<output>13/20 = around 0.65</output>

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

<gadget id="calculator">(13/20) - (2/5)</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">75 / (1/4)</gadget>
<output>300</output>

<gadget id="calculator">1 - (13/20)</gadget>
<output>7/20 = around 0.35</output>

<gadget id="calculator">300 * (7/20)</gadget>
<output>105</output>

<result>105</result>