If the minute hand rotates (1/2) round on the clock face, what is the angle of rotation of the hour hand?
钟面上如果分针转动(1/2)周，那么时针旋转的角度是多少度．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">360 / 12</gadget>
<output>30</output>

<gadget id="calculator">(1/2) * 30</gadget>
<output>15</output>

<result>15</result>