4 ounces x $8 per ounce = $32
16 ounces x $3 per ounce = $48
4 ounces + 16 ounces = 20 total ounces
$32 + $48 = $80 total cost
$80 / 20 ounces = $4 per ounce cost
9.3m questions
12.0m answers