Both the older sister and the younger sister go to school from home. The older sister walks 3.3 kilometers per hour, and the younger sister walks 2.4 kilometers per hour. The older sister asks the younger sister to go first for 3 minutes, and then the older sister starts to catch up with the younger sister. How many minutes does it take for the older sister to catch up with the younger sister?
姐姐和妹妹都从家到学校上学，姐姐每小时走3.3千米，妹妹每小时走2.4千米，姐姐让妹妹先走3分钟，然后姐姐才出发追赶妹妹，经过多少分钟姐姐可以追上妹妹？
<gadget id="calculator">40 * 3</gadget>
<output>120</output>

<gadget id="calculator">55 - 40</gadget>
<output>15</output>

<gadget id="calculator">120 / 15</gadget>
<output>8</output>

<result>8</result>