3.In Question 2 above, if 1 part of a red pigment requires 75 mL of base, how much red pigment should we mix with 1800 mL of base?

Let the required red pigment be x part
\(\frac{1}x=\frac{75ml}{1800ml}\)

\(\Rightarrow x\times 75=1\times 1800\)

\(\Rightarrow x=\frac{1800}{75}=24\; parts\)

So the required amount of red pigment =24 parts