The difference between A and B is 10, and (1/7) of A is equal to (1/4) of B. Then, what is A's number?
甲、乙两数的差是10，甲数的(1/7)和乙数的(1/4)相等，那么，甲数是多少．
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">10 * (1/4)</gadget>
<output>5/2 = around 2.5</output>

<gadget id="calculator">1 / 7</gadget>
<output>1/7 = around 0.142857</output>

<gadget id="calculator">(1/4) - (1/7)</gadget>
<output>3/28 = around 0.107143</output>

<gadget id="calculator">(5/2) / (3/28)</gadget>
<output>70/3 = around 23.333333</output>

<result>70/3 = around 23.333333</result>