The additive identity property states that for every number a, you have

You're showing this property when you write

So I am assuming that there is a 20% off sale on an item that is 20$.
Edit: I read the question wrong, the 2nd thing I wrote down is the correct answer, it will be $24 after the markup.
Answer:
Probability of red marbles = 8/25
Step-by-step explanation:
Complete question
A jar contains 8 red marbles numbered 1 to 8 and 12 blue marbles numbered 1 to 12. It alse has 5 white marbles numbered 100, 200, 300, 400, and 500. A marble is drawn at random from the jar. Find the probability of the given event.
a) The marble is red
Total number of marbles = 8+12+5 = 25
Probability of red marbles = total number of red marbles/Total marbles
Probability of red marbles = 8/25
So, 2/4 pounds of blueberries reduced is 1/2 pound of blueberries. There 16 ounces in a pound and 8 ounces in 1/2 a pound. He only bought 8 ounces of blueberries and he needs 48. Subtract 8 ounces that he already has from 48 ounces that he needs and get 40 ounces.