This is a question in the famous ancient Chinese mathematics book "Nine Chapters of Arithmetic" 2000 years ago. Please do it: the guest's horse can travel 300 miles a day, and the guest forgot to bring his clothes when he left. Only the master found out. So he took the clothes and rode his own horse to chase after him. After chasing, he gave the clothes to the guests. When he returned home, the day had passed (3/4). Question: How many miles can the owner's horse travel in a day?
这是一道2000年前我国古代数学名著《九章算术》中的一道题，请你做一做：客人的马一天能行300里，客人走时忘了带衣服，走了(1/3)天时主人才发现．于是拿了衣服骑自己的马去追，追到后将衣服交给客人，返回家中时，这天已经过了(3/4)．问：主人的马一天可以行多少里．
<gadget id="calculator">5 / 12</gadget>
<output>5/12 = around 0.416667</output>

<gadget id="calculator">(5/12) / 2</gadget>
<output>5/24 = around 0.208333</output>

<gadget id="calculator">100 / (5/24)</gadget>
<output>480</output>

<gadget id="calculator">480 + 300</gadget>
<output>780</output>

<result>780</result>