Smile and read a book, the number of pages you have read is 60% of the unread pages, and you have read 84 pages. How many pages are there in this book?
笑笑看一本书，已看的页数是未看的60%，已看了84页，这本书共有多少页．
<gadget id="calculator">60 / 100</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">84 / (3/5)</gadget>
<output>140</output>

<gadget id="calculator">140 + 84</gadget>
<output>224</output>

<result>224</result>