During the summer vacation, the school organized outstanding young pioneers to take part in summer camp activities in two different places by car. The ticket to A was 1.2 yuan, and the ticket to B was 1.5 yuan. A total of 75 tickets were bought and 99 yuan was spent. Question: What is the difference in the number of people going to places A and B?
暑假学校组织优秀少先队员乘汽车到两个不同的地方参加夏令营活动，到甲地的车票1.2元，到乙地的车票1.5元，共买了75张票，花了99元钱．问：到甲、乙两地去的人数相差多少？
<gadget id="calculator">1.2 * 75</gadget>
<output>90</output>

<gadget id="calculator">99 - 90</gadget>
<output>9</output>

<gadget id="calculator">1.5 - 1.2</gadget>
<output>0.3</output>

<gadget id="calculator">9 / 0.3</gadget>
<output>30</output>

<gadget id="calculator">75 - 30</gadget>
<output>45</output>

<gadget id="calculator">45 - 30</gadget>
<output>15</output>

<result>15</result>