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