Xiao Ming runs with his father and mother. The distance his father runs is 20 meters less than twice that of Xiao Ming, and 10 meters longer than twice that of his mother. How many meters does Xiao Ming run more than his mother?
小明和爸爸、妈妈一起跑步，爸爸跑的路程比小明的2倍少20米，比妈妈的2倍多10米，小明比妈妈多跑多少米．
<result>15</result>