Xiaoming buys 5 diaries for 5.8 yuan more than buying 1 storybook. It is known that the price of a storybook is exactly three times the price of a diary. How much is the price of a diary?
小明买5本日记本比买1本故事书多用5.8元，已知一本故事书的价钱正好是一本日记本价钱的3倍．一本日记本的价钱是多少元？
<gadget id="calculator">5 - 3</gadget>
<output>2</output>

<gadget id="calculator">5.8 / 2</gadget>
<output>2.9</output>

<result>2.9</result>