1, a, Độ rượu là: \(\dfrac{20}{20+380}.100=5^o\)
b, Độ rượu là: \(\dfrac{0,8}{0,8+1,2}.100=40^o\)
2,
\(a,V_{CH_3OH}=\dfrac{2.10}{100}=0,2\left(l\right)\\ b,V_{CH_3OH}=\dfrac{450.30}{100}=135\left(ml\right)\\ c,V_{CH_3OH}=\dfrac{30.18}{100}=5,4\left(l\right)\)