The library purchased a batch of children's books, including 42 "Idiom Stories", 18 more "Fable Stories" than "Idiom Stories", and three times as many "Fairy Tales" as "Fable Stories". Buy Fairy Tale? How many copies?
图书馆购进一批少儿图书，其中《成语故事》42本，《寓言故事》比《成语故事》多18本，《童话故事》的本数是《寓言故事》的为3倍．购进《童话故事？多少本？
<gadget id="calculator">42 + 18</gadget>
<output>60</output>

<gadget id="calculator">60 * 3</gadget>
<output>180</output>

<result>180</result>