A and B are 950 meters apart. A and B start from A at the same time, and travel back and forth between A and B. A total of 40 minutes of speaking. A walks at 40 meters per minute and B runs at 150 meters per minute. So how many times are A and B the closest to B when they meet face to face? How many meters is the distance?
A、B两地间相距950米．甲、乙两人同时由A地出发，并在A、B两地间往返行进．共行讲了40分钟．甲步行速度是每分钟40米，乙跑步速度是每分钟150米．那么甲、乙两人第几次迎面相遇时距B地最近，距离是多少米？
<gadget id="calculator">40 * 20</gadget>
<output>800</output>

<gadget id="calculator">950 - 800</gadget>
<output>150</output>

<result>150</result>