There are 180 three-bedroom apartments for teachers, the number of two-bedroom units is three-bedroom units (2/3), and the number of one-bedroom units is two-bedroom units (1/4). How many apartments are there in a teacher's apartment?
教师公寓有三居室180套，二居室的套数是三居室的(2/3)，一居室的套数是二居室的(1/4)．教师公寓有一居室多少套？
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">180 * (2/3) * (1/4)</gadget>
<output>30</output>

<result>30</result>