Cars A and B travel in the same direction from places A and B at the same time. If car A travels 60 kilometers per hour, it can catch up with car B in 5 hours; if it travels 70 kilometers per hour, it can catch up with car B in 3 hours. From the above, we can know how many kilometers per hour the second car travels (assuming that the driving speed of the second car remains unchanged).
甲、乙两车同时从A、B两地沿相同的方向行驶．甲车如果每小时行驶60千米，则5小时可追上前方的乙车；如果每小时行驶70千米，则3小时可追上前方的乙车．由上可知，乙车每小时行驶多少千米(假设乙车的行驶速度保持不变)．
<gadget id="calculator">60 * 5</gadget>
<output>300</output>

<gadget id="calculator">70 * 3</gadget>
<output>210</output>

<gadget id="calculator">300 - 210</gadget>
<output>90</output>

<gadget id="calculator">5 - 3</gadget>
<output>2</output>

<gadget id="calculator">90 / 2</gadget>
<output>45</output>

<result>45</result>