Answer:
$3.24
Explanation:
Cost of one ounce packet = 13.5 cents 
By unitary method, the cost of 24 ounce is calculated by the product of cost of one ounce packet x number of ounces
cost of 24 ounce packet = 24 x 13.5 cents = 324 cents 
Convert cents into dollars 
As we know that 100 cents = $ 1
So, 324 cents = $3.24 
Thus, teh cost of 24 ounce packet is $3.24.