What is the total surface area of rectangular solid R ?

(1) The surface area of one of the faces of R is 48.
(2) The length of one of the edges of R is 3.

Is the positive integer n an odd integer?

(1) n + 4 is a prime number.
(2) n + 3 is not a prime number.

If y is an integer and y = |x| + x, is y = 0 ?

(1) x < 0
(2) y < 1

The symbol @ represents one of the four arithmetic operations: addition, subtraction, multiplication, and division.
Is (5 @ 6) @ 2 = 5 @ (6 @ 2) ?

(1) 5 @ 6 = 6 @ 5
(2) 2 @ 0 = 2

For Manufacturer M, the cost C of producing x units of its product per month is given by C = kx + t, where C is in dollars and k and t are constants. Last month, if Manufacturer M produced 1,000 units of its product and sold all the units for k + 60 dollars each, what was Manufacturer M's gross profit on the 1,000 units?

(1) Last month, Manufacturer M's revenue from the sale of the 1,000 units was $150,000.
(2) Manufacturer M's cost of producing 500 units in a month is $45,000 less than its cost of producing 1,000 units in a month.

Whenever Martin has a restaurant bill with an amount between $10 and $99, he calculates the dollar amount of the tip as 2 times the tens digit of the amount of his bill. If the amount of Martin's most recent restaurant bill was between $10 and $99, was the tip calculated by Martin on this bill greater than 15 percent of the amount of the bill?

(1) The amount of the bill was between $15 and $50.
(2) The tip calculated by Martin was $8.

What is the value of 2x + 2y ?

(1) 3x + 5y = 60
(2) 5x + 3y = 68

Is the hundredths digit of the decimal d greater than 5 ?

(1) The tenths digit of 10d is 7.
(2) The thousandths digit of ~$\frac{d}{10}$~ is 7.

There are two types of rolls on a counter, plain rolls and seeded rolls. What is the total number of rolls on the counter?

(1) The ratio of the number of seeded rolls on the counter to the number of plain rolls on the counter is 1 to 5.
(2) There are 16 more plain rolls than seeded rolls on the counter.

In the fraction ~$\frac{x}{y}$~ , where x and y are positive integers, what is the value of y ?

(1) The least common denominator of ~$\frac{x}{y}$~ and ~$\frac{1}{3}$~ is 6.

(2) x = 1.