Little Naughty reads a technical book. He reads the whole book (1/7) on the first day and 42 pages on the second day. The ratio of the number of pages read to the number of remaining pages is 2:5. How many pages are there in total?
小淘气看一本科技书，第一天看了全书的(1/7)，第二天看了42页，这时看了的页数与剩下的页数比是2：5，这本科技书一共有多少页？
<gadget id="calculator">2 + 5</gadget>
<output>7</output>

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

<gadget id="calculator">1 / 7</gadget>
<output>1/7 = around 0.142857</output>

<gadget id="calculator">(2/7) - (1/7)</gadget>
<output>1/7 = around 0.142857</output>

<gadget id="calculator">42 / (1/7)</gadget>
<output>294</output>

<result>294</result>