Question 125248
let x ounces of herbs costing $1 be added.
Then 30(2) + (x)(1) = (30+x)(1.6)
==>   60 + x = 48 + 1.6x
==> 60 - 48 = 1.6x - x
==>  12 = 0.6x
==> 12/0.6 = x
==> x = 20

Thus 20 ounces cosing $1 need to be added,

Good luck