The number of A is (7/12), the number of B is (8/35) of the number of A, and the number of C is exactly the product of the two numbers of A and B. What is the propane number?
甲数是(7/12)，乙数是甲数的(8/35)，丙数正好是甲乙两数的乘积．丙数是多少？
<gadget id="calculator">7 / 12</gadget>
<output>7/12 = around 0.583333</output>

<gadget id="calculator">8 / 35</gadget>
<output>8/35 = around 0.228571</output>

<gadget id="calculator">(7/12) * (8/35)</gadget>
<output>2/15 = around 0.133333</output>

<gadget id="calculator">(7/12) * (2/15)</gadget>
<output>7/90 = around 0.077778</output>

<result>7/90 = around 0.077778</result>