The store shipped 700 exercise books, the lower case version is an exercise book (4/5), the Hanyu Pinyin version is a lower case version (5/7), how many copies are there of Hanyu Pinyin?
商店运来700本练习本，小楷本是练习本的(4/5)，汉语拼音本是小楷本的(5/7)，汉语拼音有几本？
<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">5 / 7</gadget>
<output>5/7 = around 0.714286</output>

<gadget id="calculator">700 * (4/5) * (5/7)</gadget>
<output>400</output>

<result>400</result>