The operation @ represents either addition, subtraction, or multiplication of integers. What is the value of 1 @ 0 ?

(1) 0 @ 2 = 2
(2) 2 @ 0 = 2

If x, y, and z are integers, is x + y + 2z even?

(1) x + z is even.
(2) y + z is even.

The sale price of a certain jacket was 15 percent less than its original price, and the sale price of a certain shirt was 10 percent less than its original price. How much greater was the original price of the jacket than the original price of the shirt?

(1) The sale price of the jacket was $83 greater than the sale price of the shirt.
(2) The original price of the jacket was $140.

If w and z are positive, is ~$\frac{w}{z}$~ < 1 ?

(1) w < z
(2) z < 4

If k is a positive integer, is k the square of an integer?

(1) k is divisible by 4.
(2) k is divisible by exactly four different prime numbers.

Is m > k ?

(1) 3m > 3k
(2) 2m > 2k

Is 4z > -6 ?

(1) z < 7
(2) z > -1

Is x < y ?

(1) 2x < 3y
(2) xy > 0

If Bob produces 36 or fewer items in a week, he is paid x dollars per item. If Bob produces more than 36 items in a week, he is paid x dollars per item for the first 36 items and 1.5 times that amount for each additional item. How many items did Bob produce last week?

(1) Last week Bob was paid a total of $480 for the items that he produced that week.
(2) This week Bob produced 2 items more than last week and was paid a total of $510 for the items that he produced this week.

The cost of a square slab is proportional to its thickness and also proportional to the square of its length. What is the cost of a square slab that is 3 meters long and 0.1 meter thick?

(1) The cost of a square slab that is 2 meters long and 0.2 meter thick is $160 more than the cost of a square slab that is 2 meters long and 0.1 meter thick.
(2) The cost of a square slab that is 3 meters long and 0.1 meter thick is $200 more than the cost of a square slab that is 2 meters long and 0.1 meter thick.