The number of students in the three classes of the sixth grade of Lianhua Primary School is 45. The number of boys in the first class of the sixth grade is the same as the number of girls in the second class of the sixth grade. The number of boys in the third class of the sixth grade accounts for 60% of the whole class. How many girls are there in total?
莲花小学六年级三个班的人数都是45，六年级一班的男生人数与六年级二班的女生人数一样，六年级三班的男生人数占全班人数的60%，六年级三个班共有女生多少人？
<gadget id="calculator">60 / 100</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">1 - (3/5)</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">45 * (2/5)</gadget>
<output>18</output>

<gadget id="calculator">45 + 18</gadget>
<output>63</output>

<result>63</result>