A car and a bicycle set off from places A and B at the same time, travel toward each other, and meet each other on the way 4 hours later. The distance between A and B is 240 kilometers, the car travels 45 kilometers per hour, how many kilometers per hour does the bicycle travel? (solution with equation)
一辆汽车和一辆自行车从甲、乙两地同时出发，相向而行，4小时后在途中相遇．甲乙两地相距240千米，汽车每小时行45千米，自行车每小时行多少千米？(用方程解答)
<gadget id="calculator">45 * 4</gadget>
<output>180</output>

<gadget id="calculator">240 - 180</gadget>
<output>60</output>

<gadget id="calculator">60 / 4</gadget>
<output>15</output>

<result>15</result>