For a certain set of n numbers, where n > 1, is the average (arithmetic mean) equal to the median?

(1) If the n numbers in the set are listed in increasing order, then the difference between any pair of successive numbers in the set is 2.
(2) The range of the n numbers in the set is 2(n - 1).

Each person attending a fund-raising party for a certain club was charged the same admission fee. How many people attended the party?

(1) If the admission fee had been $0.75 less and 100 more people had attended, the club would have received the same amount in admission fees.
(2) If the admission fee had been $1.50 more and 100 fewer people had attended, the club would have received the same amount in admission fees.

If x, y, and z are positive integers, what is the remainder when 100x + 10y + z is divided by 7 ?

(1) y = 6
(2) z = 3

If zⁿ = 1, what is the value of z ?

(1) n is a nonzero integer.
(2) z > 0

If R = 1 + 2xy + x²y², what is the value of xy ?

(1) R = 0
(2) x > 0

Three friends rented a car for a week and divided the cost equally. What was the total cost of renting the car?

(1) If the three friends had kept the car for a second week, they could have obtained the two-week rate, which was 1.5 times the cost of a one-week rental.
(2) If a fourth friend had joined the three friends and the cost had been divided equally among the four friends, the cost to each of the original three would have been reduced by $15.

A combined total of 55 lightbulbs are stored in two boxes; of these, a total of 7 are broken. If there are exactly 2 broken bulbs in the first box, what is the number of bulbs in the second box that are not broken?

(1) In the first box, the number of bulbs that are not broken is 15 times the number of broken bulbs.
(2) The total number of bulbs in the first box is 9 more than the total number of bulbs in the second box.

What is the value of x ?

(1) y - x = y - 6
(2) x + 2y = 10

A certain bag contains red, blue, and green marbles. What is the ratio of the number of green marbles to the number of red marbles in the bag?

(1) The number of blue marbles in the bag is 2 times the number of green marbles in the bag.
(2) The number of blue marbles in the bag is 3 times the number of red marbles in the bag.

If M is a finite set of negative integers, is the total number of integers in M an odd number?

(1) The product of all the integers in M is odd.
(2) The product of all the integers in M is negative.