My mother bought a set of "Science and Technology Expo" and a set of "World Geography" for a total of 112 yuan. The number of books in the two sets is the same. How many copies do each have?
妈妈买回了一套《科技博览》和一套《世界地理》共用去112元，两套书的本数相同，《科技博览》每本4.2元，《世界地理》每本9.8元，每套书各有多少本？
<gadget id="calculator">4.2 + 9.8</gadget>
<output>14</output>

<gadget id="calculator">112 / 14</gadget>
<output>8</output>

<result>8</result>