Question

To get the color dove-white, Ken mixed black paint and white paint in a ratio of 5:3. He used 20 gallons of black paint. How much white paint did he use?

Answer 1

12 gallons of white paint

divide 20 gallons by 5 to obtain 1 part of the ratio

$\frac{20}{5}$ = 4 gallons ← 1 part

white paint = 3 × 4 = 12 gallons ← 3 parts

Answer 2

He used 12 gallons of white paint.

Because 20 divided by 5 = 4. Meaning that 4 gallons is one part.

4 x 5 = 20
4 x 3 = 12