At 3:30, what is the angle between the hour and minute hands?
3点30分时，时针分针夹角是多少度．
<gadget id="calculator">30 * 2</gadget>
<output>60</output>

<gadget id="calculator">30 / 2</gadget>
<output>15</output>

<gadget id="calculator">60 + 15</gadget>
<output>75</output>

<result>75</result>