A batch of books has been repaired, 30 books have been repaired, and 1/4 are not repaired. How many books are there in this batch?
修补一批书，已修补30本，是未修补的(1/4)，这批书共有多少本？
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">30 / (1/4)</gadget>
<output>120</output>

<gadget id="calculator">120 + 30</gadget>
<output>150</output>

<result>150</result>