Use a rope 100 cm long to surround a rectangle so that the ratio of length to width is 7:3. What is the width of this rectangle in centimeters
用一根长100厘米的绳子围一个长方形，使长与宽的比是7：3．这个长方形的宽是多少厘米
<gadget id="calculator">100 / 2</gadget>
<output>50</output>

<gadget id="calculator">7 + 3</gadget>
<output>10</output>

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

<gadget id="calculator">50 * (3/10)</gadget>
<output>15</output>

<result>15</result>