Verified answer

1. A.

12500

3 dollars per disk

2500 disks = 7500

12500 +7500 =20,000 total cost

2500 * 8 dollars = 20,000 total revenue

2. C 40 shirts

280 + (40 *3.99) = 40 *10.99

1. Let number of disks = x so:

8x = 3x + 12500

5x = 12 500

x = 2500 disks therefore A

2.Let number of shirts = x so:

10.99x = 3.99x + 280

7x = 280

x = 40 shirts therefore C

Now this is very simple. Just think a little but. What is happening is this! They want to sell for the same amount of money as the bought or 'ran up on expenses'. So the amount bought will be equal to the amount of money spent. I used x as the term to be solved. i could have used any letter if I wanted! =P