It is known that the number of students in school A is 40% of the number of students in school B, the number of girls in school A is 30% of the number of students in school A, and the number of boys in school B is 42% of the number of students in school B. So what percentage of the total number of girls in the two schools accounted for the total number of students in the two schools?
已知甲校学生数是乙校学生数的40%，甲校女生数是甲校学生数的30%，乙校男生数是乙校学生数的42%．那么两校女生总数占两校学生总数的百分之几？
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">30 / 100</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">(2/5) * (3/10)</gadget>
<output>3/25 = around 0.12</output>

<gadget id="calculator">42 / 100</gadget>
<output>21/50 = around 0.42</output>

<gadget id="calculator">1 - (21/50)</gadget>
<output>29/50 = around 0.58</output>

<gadget id="calculator">(3/25) + (29/50)</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">1 + (2/5)</gadget>
<output>7/5 = around 1.4</output>

<gadget id="calculator">(7/10) / (7/5)</gadget>
<output>1/2 = around 0.5</output>

<result>1/2 = around 0.5</result>