Question

When mixing a quantity of paints, dyes of
four different colours are used in the ratio of
7 : 3 : 19 : 5. If the mass of the first dye used
is 31.5 g, determine the total mass of the dyes
used.

Answer 1

similar logic as the last problem

7 parts: 3 parts: 19 parts: 5 parts

adding these up gives us 7 + 3 + 19 + 5 = 34 parts

the mass of the first dye consists of 7/34 parts, and also has a mass of 31.5

so 7/34 = 31.5/total mass

solve for total mass