40% of A's number is B's (4/7), given that B's number is 140, what is A's number?
甲数的40%是乙数的(4/7)，已知乙数是140，甲数是多少．
<gadget id="calculator">4 / 7</gadget>
<output>4/7 = around 0.571429</output>

<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(4/7) / (2/5)</gadget>
<output>10/7 = around 1.428571</output>

<gadget id="calculator">140 * (10/7)</gadget>
<output>200</output>

<result>200</result>