Both brothers and sisters like to collect stamps very much. It turns out that they have the same number of stamps. If the elder brother gives 25 stamps to the younger sister, the younger sister will get twice as many stamps as the elder brother. How many stamps does my sister have?
兄妹两人都很喜欢收集邮票，原来有两人的邮票张数相等．如果哥哥给妹妹25张邮票，妹妹的邮票就是哥哥的2倍．原来妹妹有多少张邮票？
<gadget id="calculator">25 * 2</gadget>
<output>50</output>

<gadget id="calculator">50 + 25</gadget>
<output>75</output>

<gadget id="calculator">2 - 1</gadget>
<output>1</output>

<gadget id="calculator">75 / 1</gadget>
<output>75</output>

<result>75</result>