Put some fruit juice in three bottles, the first bottle contains (15/4) kg, the second bottle contains (13/15) of the first bottle, the third bottle contains 4 kg, How many kilograms of these juices are there in total?
把一些果汁分别装在三个瓶子里，第一个瓶子装(15/4)千克，第二个瓶子装的是第一个瓶子的(13/15)，第三个瓶子装了4千克，请问这些果汁一共有多少千克？
<gadget id="calculator">15 / 4</gadget>
<output>15/4 = around 3.75</output>

<gadget id="calculator">13 / 15</gadget>
<output>13/15 = around 0.866667</output>

<gadget id="calculator">(15/4) * (13/15)</gadget>
<output>13/4 = around 3.25</output>

<gadget id="calculator">(15/4) + (13/4) + 4</gadget>
<output>11</output>

<result>11</result>