hard math
posted by Jeanette .
The jelly Junior school color is made by mixing red paint and yellow paint. The ratio of red to yellow is 3 to 5. How much red paint should be mixed with 20 oz of yellow?

You can set up a ratio like this, with x = the amount of red paint:
3/5 : x/20
Cross multiply: 5x = 60
Solve: x = 12