The number of boys in the music group is 1 less than half the number of girls, and the number of girls is 4 less than three times the number of boys. How many people are there in this group?
音乐小组男生人数比女生人数的一半少1人，女生人数比男生人数的3倍少4人，这个小组一共有多少人．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

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

<gadget id="calculator">2 + 1</gadget>
<output>3</output>

<gadget id="calculator">(1/2) * 3</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">(3/2) - 1</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">3 / (1/2)</gadget>
<output>6</output>

<gadget id="calculator">3 * 6</gadget>
<output>18</output>

<gadget id="calculator">18 - 4</gadget>
<output>14</output>

<gadget id="calculator">6 + 14</gadget>
<output>20</output>

<result>20</result>