Multiply the same fraction by (7/10) and (14/15), the products are all integers, what is the minimum fraction?
用(7/10)、(14/15)分别乘同一个分数，积都是整数，这个分数最小应是多少？
<gadget id="calculator">2 * 3 * 5</gadget>
<output>30</output>

<gadget id="calculator">30 / 7</gadget>
<output>30/7 = around 4.285714</output>

<result>30/7 = around 4.285714</result>