Answer:
10 quarters
Explanation:
When given a ratio and one number, your goal is to scale up the ratio such that you keep the proportions equal.
The overarching proportion is 3 dimes : 2 quarters. This means that for every 2 quarters, there are three dimes.
When solving this kind of problem, you want to construct two ratios that equal one another, with the unknown value set equal to X.
Here,
3 dimes = 15 dimes
2 quarters X quarters
To solve, cross multiply, meaning multiply the numerator of one equation by the denominator of the other, and vice versa.
3X = 30
Now solve for X by dividing each side by 2
X = 10