The distance between A and B is 860 kilometers. Two cars are driving towards each other. After 4 hours, the distance between the two cars is still 100 kilometers. It is known that car A travels 100 kilometers per hour. How many kilometers does car B travel per hour? (solution by equation)
甲乙两地相距860千米，两辆汽车相向而行，4小时后两车还相距100千米，已知A车每小时行100千米，那么B车每小时行多少千米？(用方程解)
<gadget id="calculator">860 / 4</gadget>
<output>215</output>

<gadget id="calculator">100 / 4</gadget>
<output>25</output>

<gadget id="calculator">215 - 100 - 25</gadget>
<output>90</output>

<result>90</result>