Trey's Coffee Shop makes a blend that is a mixture of two types of coffee. Type A coffee costs Trey $4.80 per pound, and type B coffee costs $5.85 per pound. This month's blend used three times as many pounds of type B coffee as type A, for a total cost of $603.45. How many pounds of type A coffee were used?

Let x = the number of pounds of Type A coffee.

We know that this month's blend used 3 times as many pounds of type B coffee as type A coffee.

Total pounds of coffee = x + 3x

The total cost is:

(cost for Type A) (x) + (cost for Type B) (3x) = $603.45

$4.80x + $5.85 (3x) = $603.45

$4.80x + $17.55x = $603.45

$22.35x = $603.45

x = 603.45/22.35 = 27 pounds