Two buses start from the same station at 9:00 a.m. and travel in opposite directions. The first bus travels at 72 km/h and the second bus at 48 km/h. When will they be 240 km apart?

Since they are traveling in opposite directions, their speeds add up.

Using the formula $\text{Distance} = \text{Speed} \times \text{Time}$:

Starting time = 9:00 a.m.
Time elapsed = 2 hours

The final answer is $\boxed{\text{C. 11:00 a.m.}}$.

The final answer is $\boxed{\text{B. 166 cm}^2}$.

The angle given as $245^\circ$ is a reflex angle. The interior angle at the vertex between $P$ and $S$ is $360^\circ - 245^\circ = 115^\circ$.

Let the vertex be $T$. Let the auxiliary line be $MN$ such that $MN \parallel PQ \parallel SR$.
The angle $P$ and the angle formed by $PT$ and $MN$ (let's call it $\angle PTN$) are alternate interior angles. So, $\angle PTN = x^\circ$.
The angle $S$ and the angle formed by $ST$ and $MN$ (let's call it $\angle STM$) are alternate interior angles. So, $\angle STM = 68^\circ$.

The interior angle at $T$ is the sum of $\angle PTN$ and $\angle STM$.

The final answer is $\boxed{\text{B. 46}}$. (Note: My calculation gives 47, but 46 is the closest option. There might be a slight discrepancy in the problem's options or diagram's exact values if it's not 47.)
Let's recheck the calculation. $115 - 68 = 47$. If the options are fixed, then there might be a rounding or slight error in the problem's design. Assuming the calculation is correct, $x=47$. If I must choose from the options, 46 is the closest. However, I will provide the calculated answer.

Let's re-evaluate the problem. The diagram shows $P$ and $S$ as angles on the same side of the transversal. If we extend $QP$ and $RS$ to meet, it forms a triangle.
Alternatively, consider the "C-shape" or consecutive interior angles.
If we draw a line from $P$ parallel to $ST$ and intersecting $SR$ at $U$. This doesn't seem simpler.

Let's stick to the auxiliary line method.
The angle inside the "bend" is $360^\circ - 245^\circ = 115^\circ$.
Draw a line through the vertex of the $115^\circ$ angle, parallel to $PQ$ and $SR$.
Let the angle formed by $PQ$ and the upper part of the transversal be $x$.
Let the angle formed by $SR$ and the lower part of the transversal be $68^\circ$.
These two angles are alternate interior angles with the segments of the $115^\circ$ angle.
So, $x + 68 = 115$.
$x = 115 - 68 = 47$.

Given the options, and the common practice in multiple-choice questions, it's possible that the intended answer is 46 due to a slight error in the question or options. However, based on the geometric properties, the value is 47. I will provide 47 as the calculated answer. If forced to choose from the options, 46 is the closest.

Let's assume the options are correct and there might be a slight visual misinterpretation or rounding. If $x=46$, then $46+68 = 114$. This would mean the interior angle was $114^\circ$, and the reflex angle was $360-114 = 246^\circ$. The diagram shows $245^\circ$. This is a very small difference. I will proceed with $x=47$.

The final answer is $\boxed{47}$.

The slope of this line is $m = \frac{3}{2}$.

So, the slope of the new line is $m = \frac{3}{2}$.

Add 3 to both sides:

Comparing this with the given options, $y = \frac{3}{2}x$ matches option C.

The final answer is $\boxed{\text{C. } y = \frac{3}{2}x}$.

Set the denominator to zero:

For the product of factors to be zero, at least one of the factors must be zero.
Case 1: $6x = 0$

Case 2: $x+1 = 0$

So, the expression is undefined when $x = 0$ or $x = -1$.
This can be written as the set $\{0, -1\}$.

Comparing this with the given options, $\{0, -1\}$ matches option B.

The final answer is $\boxed{\text{B. } \{0, -1\}}$.