Xiao Ming reads a book and has read 60 pages. The ratio of the number of pages he has read to the number of pages he has not read is 3:4. How many pages does this book have?
小明看一本书，已看了60页，已看的与未看的页数的比为3：4，这本书一共有多少页？
<gadget id="calculator">60 / 3</gadget>
<output>20</output>

<gadget id="calculator">3 + 4</gadget>
<output>7</output>

<gadget id="calculator">20 * 7</gadget>
<output>140</output>

<result>140</result>