2/3 cup of oatmeal - 10 granola bars
When the number of cups of oatmeal increases, the number of granola bars also increases.
If you use for example twice as many cups of oatmeal, you'll make twice as many granola bars.
Therefore, the first step is to calculate how many times 20 cups of oatmeal is more than 2/3 cup of oatmeal. To do it, divide 20 by 2/3.

You have 30 times as many cups of oatmeal, so you'll make 30 times as many granola bars.

300 granola bars can be made with 20 cups of oatmeal.
In 1/3 cup of walnuts, she makes 1 serving of salad
Therefore, In 1 cup of walnuts, she makes 3 servings of sald.
And hence in 2 cups of walnuts, she makes 2*3 = 6 serving of salad.
So the answer of the given question is , if she has 2 cups of walnus, then she makes 6 serving of salad .