The express train and the slow train are traveling in opposite directions at the same time from A and B, which are 600 kilometers apart, and they meet at a distance of 30 kilometers from the midpoint of the two places. It is known that the express train travels 20 kilometers more than the slow train per hour, so how much is the slow train traveling per hour? rice?
快车和慢车同时从相距600千米的A、B两地相向行驶，在离两地中点30千米处相遇，已知快车每小时比慢车多行20千米，则慢车每小时行多少千米？
<gadget id="calculator">2 / 20</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">30 * (1/10)</gadget>
<output>3</output>

<gadget id="calculator">600 / 3</gadget>
<output>200</output>

<gadget id="calculator">600 / 2</gadget>
<output>300</output>

<gadget id="calculator">300 + 30</gadget>
<output>330</output>

<gadget id="calculator">330 / 3</gadget>
<output>110</output>

<gadget id="calculator">200 - 110</gadget>
<output>90</output>

<result>90</result>