#### Answer

The retailer should charge 44 dollars for the book.

#### Work Step by Step

Let s represent the selling price. The basic relationship is: selling price equals cost plus profit.
Selling price = Cost + Profit
Selling price = s
Cost = 22
Profit = 50% of the selling price = 50% $\times$ s = 0.5s
So,
s = 22 + 0.5s
0.5s = 22
Divide both sides by 0.5
s = 44
The retailer should charge 44 dollars for the book.