A person starts from point A and walks to point B. If he walks 6 kilometers per hour, he will arrive at 11:00 am. If he walks 4 kilometers per hour, he will arrive at 1:00 pm. When did this person start from point A in the morning?
某人从甲地出发步行到乙地，如每小时行6千米，则上午11时到达，如果每小时行4千米，则下午1时到达，这人是上午几时从甲地出发的？
<gadget id="calculator">4 * 2</gadget>
<output>8</output>

<gadget id="calculator">6 - 4</gadget>
<output>2</output>

<gadget id="calculator">8 / 2</gadget>
<output>4</output>

<gadget id="calculator">11 - 4</gadget>
<output>7</output>

<result>7</result>