A children's encyclopedia is about two volumes, the first volume and the second volume. 25% of the pages of the first volume is equal to (2/7) of the pages of the second volume. It is known that the first volume has 480 pages. How many pages are there in the first volume and the second volume?
一部少儿百科全书约为上、下两册，上册页数的25%等于下册页数的(2/7)，已知上册有480页，上、下两册共有多少页？
<gadget id="calculator">25 / 100</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">480 * (1/4)</gadget>
<output>120</output>

<gadget id="calculator">2 / 7</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">120 / (2/7)</gadget>
<output>420</output>

<gadget id="calculator">480 + 420</gadget>
<output>900</output>

<result>900</result>