The reciprocal of the number A is (7/15), the number A is (3/5) of the number B, what is the number B.
甲数的倒数是(7/15)，甲数是乙数的(3/5)，乙数是多少．
<gadget id="calculator">7 / 15</gadget>
<output>7/15 = around 0.466667</output>

<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">1 / (7/15) / (3/5)</gadget>
<output>25/7 = around 3.571429</output>

<result>25/7 = around 3.571429</result>