12a)
5x + 45 + 3x - 25 = 180
8x + 20 = 180
8x = 160
x = 20
12b)
2x - 5 = 2(20) - 5 = 40 - 5 = 35
3x - 25 = 3(20) - 25 = 60 - 25 = 35
y = 180 - (35+35)
y = 180 - 70
y = 110
Answer:
a) p=0.2
b) probability of passing is 0.01696
.
c) The expected value of correct questions is 1.2
Step-by-step explanation:
a) Since each question has 5 options, all of them equally likely, and only one correct answer, then the probability of having a correct answer is 1/5 = 0.2.
b) Let X be the number of correct answers. We will model this situation by considering X as a binomial random variable with a success probability of p=0.2 and having n=6 samples. We have the following for k=0,1,2,3,4,5,6
.
Recall that
In this case, the student passes if X is at least four correct questions, then

c)The expected value of a binomial random variable with parameters n and p is
. IN our case, n=6 and p =0.2. Then the expected value of correct answers is 
Answer: 15:42or simplified 5:14
Step-by-step explanation:
15 angelfish to 42 guppies
15/3= 5
42/3=14
so the ratio of 15:42 is equal to 5:14
Answer:ewlkdgvs8u9ejrmxc
Step-by-step explanation:lu7iy 6t5r47oe;8jo/ilni.ub8yu
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I had this question and SAS is the correct answer