There are two boxes of small balls, A and B. If 15 balls are taken from A and given to B, A belongs to B (5/7); if 17 balls are taken from B to A, B belongs to A (5/7). How many small balls are there in Box A?
有甲乙两盒小球，如果从甲种取出15个给乙后，甲是乙的(5/7)；若从乙中取出17个给甲后，乙是甲的(5/7)．甲盒原有小球多少个．
<gadget id="calculator">15 + 17</gadget>
<output>32</output>

<gadget id="calculator">5 + 7</gadget>
<output>12</output>

<gadget id="calculator">7 / 12</gadget>
<output>7/12 = around 0.583333</output>

<gadget id="calculator">5 / 12</gadget>
<output>5/12 = around 0.416667</output>

<gadget id="calculator">(7/12) - (5/12)</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">32 / (1/6)</gadget>
<output>192</output>

<gadget id="calculator">192 * (5/12)</gadget>
<output>80</output>

<gadget id="calculator">80 + 15</gadget>
<output>95</output>

<result>95</result>