In a ratio, the product of two inner terms is the smallest prime number, and one of the outer terms is known to be (2/7), so what is the other outer term.
在一个比例中，两个内项相乘的积是最小的质数，已知其中一个外项是(2/7)，那么另一个外项是多少．
<gadget id="calculator">2 / 7</gadget>
<output>2/7 = around 0.285714</output>

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

<result>7</result>