The graph of which of the following equations is a straight line that is parallel to line l in the figure above?

The function f is defined by ~$f\left ( x \right )=\sqrt{x}-10$~ for all positive numbers x.  If u = f(t) for some positive numbers t and u.  What is t in terms of u?

If a certain coin is flipped, the probability that the coin will land heads is ~$\frac{1}{2}$~.  If the coin is flipped 5 times, what is the probability that it will land heads up on the first 3 flips and not on the last 2 flips?

If x ≠ 0, then ~$\left ( x+\frac{1}{x} \right )^{2}-\left ( x-\frac{1}{x} \right )^{2}=$~

Box W and Box V each contain several blue sticks and red sticks, and all of the red sticks have the same length.  The length of each red stick is 18 inches less than the average length of the sticks in Box W and 6 inches greater than the average length of the sticks in Box V.  What is the average (arithmetic mean) length, in inches, of the sticks in Box W minus the average length, in inches, of the sticks in Box V?

The sequence a1, a2, … , a n, … is such that an = 2an-1 - x for all positive integers n ≥ 2 and for certain number x.  If a5 = 99 and a3 = 27, what is the value of x?

In the figure shown, two identical squares are inscribed in the rectangle.  If the perimeter of the rectangle is ~$18\sqrt{2}$~, then what is the perimeter of each square?

If 5x = 2y and xy ≠ 0, then is what percent of y?

In the figure shown, the triangle is inscribed in the semicircle.  If the length of line segment AB is 8 and the length of line segment BC is 6, what is the length of arc ABC?

The population of City X is 50 percent of the population of City Y.  The population of City X is what percent of the total population of City X and City Y?