Question 1156892
4 oz*0.28=1.12 oz pure alcohol
x oz* 0.14=0.14 x pure
4+x oz *0.18=0.72+0.18x pure
so 1.12+0.14x=0.72+0.18x
0.40=0.04x
4x=40, multiplying by 100
x=10 oz 18%
C