A supermarket shipped 300 packs of math books, and the English books shipped were both math books (4/5) and composition texts (6/7). How many composition books did the supermarket ship?
某超市运来300包数学本，运来的英语本是数学本的(4/5)，又是作文本的(6/7)，超市运来作文本多少本？
<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">6 / 7</gadget>
<output>6/7 = around 0.857143</output>

<gadget id="calculator">(4/5) / (6/7)</gadget>
<output>14/15 = around 0.933333</output>

<gadget id="calculator">300 * (14/15)</gadget>
<output>280</output>

<result>280</result>