Question

A mixture of paint is prepared by mixing 1 part of red pigments with 8 parts of base. If 1 part of a red pigment requires 75 mL of base, how much red pigment should we mix with 1800 mL of base?

Answer 1

Let the parts of red pigment required to mix with 1800 mL of base be x.
The given information in the form of a table is as follows. 

Parts of red pigment	1	x
Parts of base (in mL)	75	1800

The parts of red pigment and the parts of base are in direct proportion.
Therefore, we obtain.
\(\frac{1 }{ 75} = \frac{x}{ 1800}\)

\(x = \frac{1 × 1800 }{ 75}\)
\(x = 24\)
Thus, 24 parts of red pigments should be mixed with 1800 mL of base.