Mary's Coffee Shop makes a blend that is a mixture of two types of coffee. Type A coffee costs Mary $$5\mathrm{.}95$ per pound, and type B coffee costs $$4\mathrm{.}50$ per pound. This month, Mary made $139$ pounds of the blend, for a total cost of $$754\mathrm{.}55.$ How many pounds of type B coffee did she use?

Number of pounds of type B coffee: