The quotient of dividing the number A by the number B is 1.5. If the number A increases by 20, the number A is 4 times that of B. What is the original number of A?
甲数除以乙数的商是1.5，如果甲数增加20，则甲数是乙的4倍．原来甲数是多少．
<gadget id="calculator">4 - 1.5</gadget>
<output>2.5</output>

<gadget id="calculator">20 / 2.5</gadget>
<output>8</output>

<gadget id="calculator">8 * 1.5</gadget>
<output>12</output>

<result>12</result>