【Question 12】  
$A$ and $B$ are 1200 meters apart. Dacheng starts from $A$ and after 6 minutes, Xiaogong starts from $B$. They meet 12 minutes later. Dacheng walks 20 meters more per minute than Xiaogong. Xiaogong walks $\qquad$ meters per minute.
【Analysis and Solution】Travel problem.

Da Cheng walks 20 meters more per minute than Xiao Gong; in $6+12=18$ minutes, Xiao Gong walks $20 \times 18=360$ meters less than Da Cheng; in $12+18=30$ minutes, Xiao Gong walks $1200-360=840$ meters; Xiao Gong walks $840 \div 30=28$ meters per minute.