Sourdough Loaves Sold

A local bakery sells two types of bread: whole wheat and sourdough. On Monday, they sold a total of 120 loaves of bread, and they sold twice as many whole wheat loaves as sourdough loaves.
Let $x$ represent the number of sourdough loaves sold. Write an equation to express the total sales and solve for $x$.

What is the number of sourdough loaves sold?