At a certain clothing store, customers who buy 2 shirts pay the regular price for the first shirt and a discounted price for the second shirt. The store makes the same profit from the sale of 2 shirts that it makes from the sale of 1 shirt at the regular price. For a customer who buys 2 shirts, what is the discounted price of the second shirt?

（1）The regular price of each of the 2 shirts the customer buys at the clothing store is $16.

（2）The cost to the clothing store of each of the 2 shirts the customer buys is $12.

Did the population of Town C increase by at least 100 percent from the year 2000 to the year 2010?

（1）The population of Town C in 2000 was 2/3 of the population in 2005.

（2）The population of Town C increased by a greater number of people from 2005 to 2010 than it did from 2000 to 2005.

A certain computer company produces two different monitors, P and Q. In 2010, what was the net profit from the sale of the two monitors?

（1）Of the company's expenses in 2010, rent and utilities totaled $500,000.

（2）In 2010, the company sold 50,000 units of monitor P at $300 per unit and 30,000 units of monitor Q at $650 per unit.

What is the volume of the right circular cylinder X?

（1）The height of X is 20.

（2）The base of X has area 25π.

In the figure shown, is L₁ ∥  L₂ ?

（1）r = s

（2）t = u

If all of the six faces of a concrete block are rectangular, what is the volume of the block?

（1）Each of the four lateral faces of the block has an area of 200 square inches.

（2）The top of the block is square and has an area of 400 square inches.

There are 2 groups of students who took a history test. Was the average (arithmetic mean) score of the students in Group A higher than the average score of the students in Group B who took the test?

（1）Of the students who took the test, 10 were in Group A and 12 were in Group B.

（2）On the test, the highest score achieved was achieved by a Group B student and the lowest score achieved was achieved by a Group A student.

In the xy-coordinate plane, what are the x-coordinates of the four vertices of square JKMN?

（1） J and M are on the x-axis, and K and N are on the y-axis.

（2） The center of the square is at the origin.

In the xy-coordinate plane above, what are the coordinates of point N?

（1）Triangle MNP is equilateral.

（2）Point M has coordinates (-4,0).

If s is an integer, is 24 a divisor of s?

(1)Each of the numbers 3 and 8 is a divisor of s. 

(2) Each of the numbers 4 and 6 is a divisor of s.