(2/5) of the number A is equal to 35% of the number B, the number B is 80, what is the number A?
甲数的(2/5)等于乙数的35%，乙数是80，甲数是多少．
<gadget id="calculator">35 / 100</gadget>
<output>7/20 = around 0.35</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(7/20) / (2/5)</gadget>
<output>7/8 = around 0.875</output>

<gadget id="calculator">80 * (7/8)</gadget>
<output>70</output>

<result>70</result>