A book costs $4 more than a CD. The CD is 30% cheaper than a $20 album. How much does the book cost?
The CD is 30/100 * 20 = $
<gadget id="calculator">30/100*20</gadget>
<output>6</output>
6 cheaper than the album.
So the cost of the CD is 20 - 6 = $
<gadget id="calculator">20-6</gadget>
<output>14</output>
14.
The book is $4 more expensive than the CD, which means it cost 14 + 4 = $
<gadget id="calculator">14+4</gadget>
<output>18</output>
18.

<result>18</result>