The sum of number A and number B is 30. If the decimal point of number A is moved to the left by one bit, it is exactly half of the number B. What is the product of the two numbers A and B?
甲数与乙数的和为30，若将甲数的小数点向左移一位恰好是乙数的一半，则甲乙两数的积是多少．
<gadget id="calculator">2 / 10</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 + (1/5)</gadget>
<output>6/5 = around 1.2</output>

<gadget id="calculator">30 / (6/5)</gadget>
<output>25</output>

<gadget id="calculator">25 * (1/5) * 25</gadget>
<output>125</output>

<result>125</result>