On Sunday, Xiao Ming went to Xinhua Bookstore to buy two books, "Ocean World" and "Fairy Tale World". How much is the price of the book?
星期天，小明去新华书店买了《海洋世界》和《童话世界》两本书，共用去30元，《海洋世界》的价钱是《童话世界》的(7/8)，《海洋世界》这本书的价钱是多少元？
<gadget id="calculator">7 + 8</gadget>
<output>15</output>

<gadget id="calculator">7 / 15</gadget>
<output>7/15 = around 0.466667</output>

<gadget id="calculator">30 * (7/15)</gadget>
<output>14</output>

<result>14</result>