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