Looks good to me. Calculation is correct. Although you might want to add to #1 your description; that the width of the rectangle is the circumference of the circle (w = 2πr) and that you add the surfaces together to get the total surface area.
total surface area = area of rectangular part + area of circular parts
SA = 2πrL + 2πr²
Correct answer is C.
Line

intersects y-axis at -2 and passes through the point (3,-1).
Line must be dashed, because the inequality sign is ">".
Point (0,0) must lie in the solution set because it satisfies inequality

.
Answer:
90
Step-by-step explanation:
The mode of the set is the number that occurs the most. In this case, 90 occurs more than any of the other terms. You can keep track using a tally chart:
80 |
82 |
90 ||
92 |
86 |
74 |
68 |
88 |
98 |