Answer:

Step-by-step explanation:


comparing with equation







For twelve people you need: 2 litres of lemon-lime soda, 1 pint of sherbet and 3 cups of ice tea.
For 36 people you need: 6 litres of lemon-lime soda, 3 pints of sherbet and 9 cups of ice.
Answer:
- 280 student tickets
- 520 adult tickets
Step-by-step explanation:
You may recognize that you are given two relationships between two unknowns. You can write equations for that.
You are asked for numbers of adult tickets and of student tickets. It often works well to let the values you're asked for be represented by variables. We can choose "a" for the number of adult tickets, and "s" for the number of student tickets. Then the problem statement tells us the relationships ...
a + s = 800 . . . . . . 800 tickets were sold
12.50a + 7.50s = 8600 . . . . . . . revenue from sales was 8600
(You are supposed to know that the revenue from selling "a" adult tickets is found by multiplying the ticket price by the number of tickets: 12.50a.)
___
You can solve these two equations any number of ways. One way is to do it by <em>elimination</em>. We can multiply the first equation by 12.50 and subtract the second equation:
12.50(a +s) -(12.50a +7.50s) = 12.50(800) -(8600)
5s = 1400 . . . . simplify. (The "a" variable has been eliminated.)
s = 280 . . . . . . divide by 5
Then the number of adult tickets can be found from the first equation:
a + 280 = 800
a = 520
280 student tickets and 520 adult tickets were sold.
Answer:
0.5234 = 52.34% probability that at least three of these students are in favor of the proposal to change the dress code.
Step-by-step explanation:
For each student, there are only two possible outcomes. Either they are in favor, or they are not. Students are independent. This means that we use the binomial probability distribution to solve this question.
Binomial probability distribution
The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

In which
is the number of different combinations of x objects from a set of n elements, given by the following formula.

And p is the probability of X happening.
18% of the students are in favor of changing the dress code.
This means that 
You randomly select 15 students
This means that 
What is the probability that at least three of these students are in favor of the proposal to change the dress code?
This is

In which

In which






0.5234 = 52.34% probability that at least three of these students are in favor of the proposal to change the dress code.
You're given an angle, the side adjacent to the angle, and are looking for the hypotenuse.
Use cosine = adjacent / hypotenuse.
cos(60) = 2√(3) / x
Rearrange the equation to solve for x (multiply both sides by x, then divide both sides by cos(60)).
x = (2√(3)) / (cos(60))
x equates to about 6.928