It is known that 2 is not greater than A, A is less than B, B is not greater than 7, A and B are both natural numbers, then what is the minimum value of ((A+B)/(AB)).
已知2不大于A，A小于B，B不大于7，A和B都是自然数，那么((A+B)/(AB))的最小值是多少．
<gadget id="calculator">6 + 7</gadget>
<output>13</output>

<gadget id="calculator">6 * 7</gadget>
<output>42</output>

<gadget id="calculator">13 / 42</gadget>
<output>13/42 = around 0.309524</output>

<result>13/42 = around 0.309524</result>