Answer:
Option is right
Step-by-step explanation:
Given that bella want to know what the students at her school think of her show. which is the BEST group to survey to find this information
For getting accurate results she must select a random sample without bias
For this option a will not serve since she selects only students she recognizes.
Option B may not be right, as during show on the face they may not give correct opinion
C is right as a random sample is taken
D is wrong as the first 30 students may not be at random.
So option C is right
Answer:

Step-by-step explanation:
A road is perpendicular to a highway leading to a farmhouse d miles away.
An automobile passes through the point of intersection with a constant speed
= r mph
Let x be the distance of automobile from the point of intersection and distance between the automobile and farmhouse is 'h' miles.
Then by Pythagoras theorem,
h² = d² + x²
By taking derivative on both the sides of the equation,




When automobile is 30 miles past the intersection,
For x = 30

Since 
Therefore,


Answer:
a: the second choice, and pounds=10
b. the second choice, and points=90.
Step-by-step explanation:
for a , you just divide the pounds by the price and you get 5 for each.
for b, you just divide the points by the tickets and you get 9 each.