The answer is 13 because after you subtract 28 and 9.99, you then divide that number by 1.29 and you only take the whole number
24 bottles @ $3 = 8 bottles per dollar
12.5 cents per bottle
36 bottles @ $4 = 9 bottles per dollar
11.1 cents per bottle
D is the answer vaporizing
The percentage error is 23%
Explanation:
The estimated total cost of the groceries = $50
The actual cost of the groceries = $65
To find the error value, we need to subtract the value of actual cost and total cost of the groceries.
Thus,
error value = actual cost - total cost
error value 
Hence, error value = $15
The formula to determine the percent error is given by

Substituting the values in the formula, we get,

Rounding off the value, we have, 23%
Thus, the percentage error is 23%