If x is a negative number, what is the value of x ?

(1) x² = 1
(2) x² + 3x + 2 = 0

If the terms of a sequence are t₁, t₂, t₃, . . . , t_n, what is the value of n ?

(1) The sum of the n terms is 3,124.
(2) The average (arithmetic mean) of the n terms is 4.

For each customer, a bakery charges p dollars for the first loaf of bread bought by the customer and charges q dollars for each additional loaf bought by the customer. What is the value of p ?

(1) A customer who buys 2 loaves is charged 10 percent less per loaf than a customer who buys a single loaf.
(2) A customer who buys 6 loaves of bread is charged 10 dollars.

If n is an integer between 10 and 99, is n < 80 ?

(1) The sum of the two digits of n is a prime number.
(2) Each of the two digits of n is a prime number.

Is the integer k divisible by 4 ?

(1) 8k is divisible by 16.
(2) 9k is divisible by 12.

Is x less than 20 ?

(1) The sum of x and y is less than 20.
(2) y is less than 20.

If x and y are integers, what is the value of x + y ?

(1) 690 < x < y < 696
(2) 692 < x < y < 695

What is the average (arithmetic mean) of eleven consecutive integers?

(1) The average of the first nine integers is 7.
(2) The average of the last nine integers is 9.

A bookstore that sells used books sells each of its paperback books for a certain price and each of its hardcover books for a certain price. If Joe, Maria, and Paul bought books in this store, how much did Maria pay for 1 paperback book and 1 hardcover book?

(1) Joe bought 2 paperback books and 3 hardcover books for $12.50.
(2) Paul bought 4 paperback books and 6 hardcover books for $25.00.

Is the integer x divisible by 6 ?

(1) x + 3 is divisible by 3.
(2) x + 3 is an odd number.