Two points on a level ground are 500m apart. The angles of elevation from these points to the top a tower are 40° and 60° respectively. If the two points and the base of the tower are in the same vertical plane, find the height of the tower.

Here are the solutions to the problems:

1) Question 1: If $\frac{x}{y} = \frac{1}{2}$, then $\frac{x+y}{x-y}$ is equal to
Options: A. $\frac{1}{3}$ B. 3 C. $\frac{1}{2}$ D. 1

Step 1: From the given ratio $\frac{x}{y} = \frac{1}{2}$, we can express $y$ in terms of $x$:

$$y = 2x$$

Step 2: Substitute $y = 2x$ into the expression $\frac{x+y}{x-y}$:

$$$$