Maria has a total of 90 apples and oranges combined. She has twice as many apples as oranges. How many apples does Maria have?

Let x represent the number of oranges Maria has, then the number of apples she has can be expressed as 2x.

Using the equation for the total number of fruits, we can set up the equation: $$x + 2x = 90$$. Solve for x to find the number of oranges, and then calculate the number of apples.