Answer:
30 units.
Step-by-step explanation:
Let x be number of milk units sold.
It has been given that You begin the week with 20 units of milk. You purchase 40 units. Therefore, total units of milk will be
units.
It has been given that your ending inventory for the week is 30 units, which means after selling x units from 60 units you are left with 30 units.
We can set this information in an equation as:



Therefore, you have sold 30 units.
Since we know that 1/4 is equal to 25%, or 0.25 in decimal form, we are able to work with 0.75 in the expression.
We are told to use j as the original price of the jeans, so we can set up the expression:

to represent the cost of the jeans with the discount.
Then to simplify, we simply take out j as a common factor, and solve what's in the parentheses:

or 
Using this equation, we can solve for the b part of the question. If the pair of jeans originally costs $60, plug in 60 to where j is in the expression:


Therefore, the cost of the jeans after the discount is C) $45.
In cases like these, you simply have to multiply the choices you have for each step.
In fact, you can choose between 4 different crusts. For each of these crusts you can choose 4 different sauces. This means that there are
choices at this point. In fact, if we call the crust options 1,2,3,4 and the sauce options A,B,C,D, the 16 possible combinations are

From here, you keep going multiplying the number of options for each step, for a total of
