P + s = 200......p = 200 - s
20p + 15s = 3400
20(200 - s) + 15s = 3400
4000 - 20s + 15s = 3400
-20s + 15s = 3400 - 4000
-5s = - 600
s = -600/-5
s = 120 <=== there were 120 standard tickets sold
p + s = 200
p + 120 = 200
p = 200 - 120
p = 80 <=== there were 80 premium tickets sold
Answer:
i think probably x∉∅
Step-by-step explanation:
3x-7 = 3x+9
-7 = 9
so x∉∅
First, we need to get all of the r's on the same side. To do this, we need to subtract "r" from both sides.
0.25r - 0.125 + 0.5r - r = 0.5 + r - r
0.25r - 0.125 +0.5r - r = 0.5
Now, we need to add like terms.
0.25r + 0.5r - r - 0.125 = 0.5
-0.25r - 0.125 = 0.5
Now, we need to get the "r" variable by itself.
-0.25r - 0.125 + 0.125 = 0.5 + 0.125
-0.25r = 0.625
Now, we divide both sides by -0.25
(-0.25r) / (-0.25) = 0.625 / (-0.25)
r = -2.5
Answer:
Standard deviation 46.3
Step-by-step explanation:
A 28% of the distribution is equivalent to a z score of -0.5828, you can use a z table to find that.
Z score is calculated as follows:

x is the number being evaluated
μ is the mean
σ is the standard deviation
And it is used to calculate how many standard deviations you are from the mean of the sample.
Replacing with the known information you can calculate the standard deviation:

4n + 7 - 5n ≥ 22
-n ≥ 15
n ≤ -15