A certain school has 120 boys and 80 girls participating in the mathematics competition, 120 girls and 80 boys participating in the Chinese competition. It is known that there are a total of 260 students participating in the competition, of which 75 boys participated in both subjects. So how many girls are there who only participate in the mathematics competition but not the language competition?
某校参加数学竞赛有120名男生，80名女生，参加语文竞赛的有120名女生，80名男生，已知该校总共有260名学生参加竞赛，其中75名男生两科竞赛都参加了，那么只参加数学竞赛而没有参加语文竞赛的女生有多少人？
<gadget id="calculator">80 - 75</gadget>
<output>5</output>

<gadget id="calculator">120 + 5</gadget>
<output>125</output>

<gadget id="calculator">260 - 125</gadget>
<output>135</output>

<gadget id="calculator">80 - 135</gadget>
<output>-55</output>

<gadget id="calculator">120 + (-55)</gadget>
<output>65</output>

<gadget id="calculator">80 - 65</gadget>
<output>15</output>

<result>15</result>