The cover of a math book is 24 cm long, which is 7.2 cm longer than its width. What is the width of the cover of the math book?
数学书封面长24厘米，比它的宽多7.2厘米．数学书封面的宽是多少厘米？
<gadget id="calculator">24 - 7.2</gadget>
<output>16.8</output>

<result>16.8</result>