Three cars, fast, medium and slow, drive from point A to point B along the same highway at the same time, and a cyclist is also traveling in the same direction on the way. The three cars catch up with the cyclist with 7, 8, and 14 points respectively. It is known that each branch of the express train is 400 meters, and each branch of the slow train is 300 meters. Find the speed of the medium-speed train.
快、中、慢三辆车同时从A地沿同一公路开往B地，途中有一骑车人也同方向行进．这三辆车分别用7分、8分、14分追上骑车人．已知快车每分行400米，慢车每分行300米，求中速车的速度．
<gadget id="calculator">400 - 300</gadget>
<output>100</output>

<gadget id="calculator">14 - 7</gadget>
<output>7</output>

<gadget id="calculator">7 / 7</gadget>
<output>1</output>

<gadget id="calculator">100 * 1</gadget>
<output>100</output>

<gadget id="calculator">300 - 100</gadget>
<output>200</output>

<gadget id="calculator">400 - 200</gadget>
<output>200</output>

<gadget id="calculator">7 / 8</gadget>
<output>7/8 = around 0.875</output>

<gadget id="calculator">200 * (7/8)</gadget>
<output>175</output>

<gadget id="calculator">200 + 175</gadget>
<output>375</output>

<result>375</result>