Dongdong and 4 good friends went to the library to borrow books. They borrowed 18 books in total, and the borrowing fee for each book was 1.5 yuan. How much did each of them pay on average?
东东和4个好朋友到图书馆去借书，他们共借出了18本书，每本书的借阅费为1.5元，他们平均每个人要付借阅费多少元？
<gadget id="calculator">4 + 1</gadget>
<output>5</output>

<gadget id="calculator">1.5 / 5</gadget>
<output>0.3</output>

<gadget id="calculator">18 * 0.3</gadget>
<output>5.4</output>

<result>5.4</result>