Xiaohong walks to school, walking 60 meters per minute. After 11 minutes away from home, her mother finds that Xiaohong’s math book is forgotten at home, and immediately takes her math book to chase Xiaohong at a speed of 280 meters per minute. Catch up with Xiaohong.
小红步行上学，每分钟走60米，离家11分钟后，妈妈发现小红的数学书忘在家中，立即带着数学书以每分钟280米的速度去追小红，妈妈出发多少分钟后追上小红．
<gadget id="calculator">60 * 11</gadget>
<output>660</output>

<gadget id="calculator">280 - 60</gadget>
<output>220</output>

<gadget id="calculator">660 / 220</gadget>
<output>3</output>

<result>3</result>