In the sixth grade mathematics interest group, the number of girls accounted for the total number (8/15), and later 3 boys joined, and the number of girls accounted for the total number (4/9). How many boys are there in the mathematics interest group?
六年级数学兴趣小组中，女生人数占总人数的(8/15)，后来又有3名男生参加，这时女生人数占总人数的(4/9)．数学兴趣小组现有多少名男生．
<gadget id="calculator">4 / 9</gadget>
<output>4/9 = around 0.444444</output>

<gadget id="calculator">1 / (4/9)</gadget>
<output>9/4 = around 2.25</output>

<gadget id="calculator">8 / 15</gadget>
<output>8/15 = around 0.533333</output>

<gadget id="calculator">1 / (8/15)</gadget>
<output>15/8 = around 1.875</output>

<gadget id="calculator">(9/4) - (15/8)</gadget>
<output>3/8 = around 0.375</output>

<gadget id="calculator">3 / (3/8)</gadget>
<output>8</output>

<gadget id="calculator">8 * (9/4)</gadget>
<output>18</output>

<gadget id="calculator">18 - 8</gadget>
<output>10</output>

<result>10</result>