smc

(similar to Solution 1, however a slightly more obvious way) Say that x = # of 2-pt shots y = # of 3-pt shots Because the total number of shots is $30$, $x+y=30$ However, Shenille was only successful on $20\%$ of the 3-pt shots, and $30\%$ of the 2-pt shots, so $0.2x+0.3y$ = #number of successful shots For each successful shot, there is an associated number of points with it. Therefore, $0.2(x)(3)+(0.3)(y)(2)$ = her score this evaluates to $0.6(x+y)$ = her score $x+y$ is already determined to be 30, so her score is $0.6(30)=\boxed{18}$