Teacher Li bought 12 pairs of table tennis rackets, and Teacher Zhang bought 9 pairs of the same table tennis rackets. Teacher Li paid 144 yuan less than Teacher Zhang. How much is each pair of table tennis rackets?
李老师买了12副乒乓球拍，张老师买了9副同样的乒乓球拍，李老师比张老师少付144元，每副乒乓球拍多少元．
<gadget id="calculator">12 - 9</gadget>
<output>3</output>

<gadget id="calculator">144 / 3</gadget>
<output>48</output>

<result>48</result>