The male teachers in Xishan Middle School accounted for (1/4) of the whole school's teachers. After 6 male teachers came, the male teachers accounted for (2/5) of the whole school's teachers. How many teachers are there in Xishan Middle School now?
西山中学的男老师占全校老师的(1/4)，当来了6名男老师后，男老师占全校老师的(2/5)，西山中学现在有老师多少人？
<gadget id="calculator">5 - 2</gadget>
<output>3</output>

<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">4 - 1</gadget>
<output>3</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">(2/3) - (1/3)</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (2/5)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">6 / (1/3) / (3/5)</gadget>
<output>30</output>

<result>30</result>