其它
Orange peel is a type of orange color mixing red and yellow paint with a ratio of $1:2$. In the shop, red paint is selling at $5$ dollars per ounce and yellow paint is selling at $4$ dollars per ounce. If Richard wants to make $12$ ounces of orange peel, how much money does she need? 
Overseas Competition->Knowledge Point->Word Problem Modules->Solving Problems Involving Fractions and Percentages->Finding the Rate
$12\div (1+2)=4$  $4\times (1\times 5+2\times 4)=4\times 13=52$ 