In the school library, nature books account for (3/10), story books account for (5/12), and social books account for (3/8). What percentage of story books and social books account for the total? How much more social books are there than nature books?
学校图书馆中自然类图书占(3/10)，故事类图书占(5/12)，社会类图书占(3/8)，故事书和社会类书一共占几分之几？社会类书比自然类书多几分之几？
<gadget id="calculator">3 / 8</gadget>
<output>3/8 = around 0.375</output>

<gadget id="calculator">3 / 10</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">(3/8) - (3/10)</gadget>
<output>3/40 = around 0.075</output>

<result>3/40 = around 0.075</result>