Xiao Ming's home is 6 kilometers away from the school. Every day, Xiao Ming rides his bicycle to school at a certain speed, and arrives exactly 5 minutes before class starts. On this day, Xiao Ming set off 10 minutes later than usual, so he speeded up his bicycle and arrived at the school one minute before class. It is known that Xiao Ming's speed after speeding up is 1.5 times of normal speed. What is the speed of Xiao Ming's bicycle in kilometers per hour?
小明家与学校相距6千米．每天小明都以一定的速度骑自行车去学校，恰好在上课前5分钟赶到．这天，小明比平时晚出发了10分钟，于是他提速骑车，结果在上课前l分钟赶到了学校．已知小明提速后的速度是平时的1.5倍．小明平时骑车的速度是每小时多少千米．
<result>20</result>