When two numbers are multiplied, if the multiplicand increases by 12 and the multiplier remains unchanged, the product increases by 60; if the multiplicand remains unchanged and the multiplier increases by 12, the product increases by 144. So what is the original product.
两数相乘，若被乘数增加12，乘数不变，则积增加60；若被乘数不变，乘数增加12，则积增加144．那么原来的积是多少．
<gadget id="calculator">144 / 12</gadget>
<output>12</output>

<gadget id="calculator">60 / 12</gadget>
<output>5</output>

<gadget id="calculator">12 * 5</gadget>
<output>60</output>

<result>60</result>