There are two types of beverages. The capacity of the large bottle is 1.5 liters, which is 0.9 liters less than 4 times the capacity of the small bottle. How many liters is the capacity of the small bottle?
有两种规格的饮料，大瓶容量是1.5升，比小瓶容量的4倍少0.9升，小瓶容量是多少升？
<gadget id="calculator">1.5 + 0.9</gadget>
<output>2.4</output>

<gadget id="calculator">2.4 / 4</gadget>
<output>0.6</output>

<result>0.6</result>