There are some books on Xiao Ming's bookshelf, the number of books does not exceed 150, among which (1/5) are story books, (2/9) are science and technology books, how many books can be placed on the bookshelf at most.
小明的书架上放着一些书，书的本数不超过150本，其中(1/5)是故事书，(2/9)是科技书，书架上最多放着多少本书．
<gadget id="calculator">5 * 9 * 1 * 3</gadget>
<output>135</output>

<result>135</result>