Xiao Ming read 30 pages of an extracurricular reading, which happened to be 1/5 of the remaining pages. How many pages are there in this extracurricular reading?
一本课外读物，小明看了30页，正好是剩下页数的(1/5)，这本课外读物共有多少页？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">30 / (1/5)</gadget>
<output>150</output>

<gadget id="calculator">150 + 30</gadget>
<output>180</output>

<result>180</result>