BRAINLIESTTT ASAP!<br><br> please answer

Factor the following, I will give 5 stars and thanks.

tigry1 [53]

Answer:

13) $n=-3,-7$

14) $b=-4,-8$

15) $m=-7$

16) $a=-5,-7$

Step-by-step explanation:

5 0

2 years ago

you have a bag with 20 marbles 2 yellow 5 green 12 red and 1 blue which of the following statements are true? Select all that ap

NNADVOKAT [17]

An event has probability 1 if you're certain that it will happen. You are sure to pick a marble that's either yellow, green, red, or blue. So, this probability is 1.
There are more yellow marbles than blue marbles, so it's actually more likely that you'll pick a yellow one, rather than the blue one.
The probability of picking a green marble is given by the number of green marbles divided by the total number of marbles. Compute this ratio and see what you get.
Similarly, the probability of picking a black marble is given by the number of black marbles divided by the total number of marbles. There are no black marbles, so...

5 0

3 years ago

According to a study, 50 % of adult smokers started smoking before 21 years old. 5 smokers 21 years old or older are randomly se

belka [17]

Answer:

a) The probability that at least 2 of them started smoking before 21 years of age is 0.1875 = 18.75%.

b) The probability that at most 4 of them started smoking before 21 years of age is 0.96875 = 96.875%.

c) The probability that exactly 3 of them started smoking before 21 years of age is 0.3125 = 31.25%.

Step-by-step explanation:

For each smoker, there are only two possible outcomes. Either they started smoking before 21 years old, or they did not. Smokers are independent, which means that the binomial probability distribution is used 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.

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

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

$C_{n,x} = \frac{n!}{x!(n-x)!}$

And p is the probability of X happening.

50% of adult smokers started smoking before 21 years old.

This means that $p = 0.5$

5 smokers 21 years old or older are randomly selected, and the number of smokers who started smoking before 21 is recorded.

This means that $n = 5$ .

a) The probability that at least 2 of them started smoking before 21 years of age is

This is:

$P(X \geq 2) = 1 - P(X < 2)$

In which

$P(X < 2) = P(X = 0) + P(X = 1)$

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 0) = C_{5,0}.(0.5)^{0}.(0.5)^{5} = 0.03125$

$P(X = 1) = C_{5,1}.(0.5)^{1}.(0.5)^{4} = 0.15625$

$P(X < 2) = P(X = 0) + P(X = 1) = 0.03125 + 0.15625 = 0.1875$

The probability that at least 2 of them started smoking before 21 years of age is 0.1875 = 18.75%.

b) The probability that at most 4 of them started smoking before 21 years of age is

This is:

$P(X \leq 4) = 1 - P(X = 5)$

In which

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 5) = C_{5,5}.(0.5)^{5}.(0.5)^{0} = 0.03125$

$P(X \leq 4) = 1 - P(X = 5) = 1 - 0.03125 = 0.96875$

The probability that at most 4 of them started smoking before 21 years of age is 0.96875 = 96.875%.

c) The probability that exactly 3 of them started smoking before 21 years of age is

This is P(X = 3). So

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 3) = C_{5,3}.(0.5)^{3}.(0.5)^{2} = 0.3125$

The probability that exactly 3 of them started smoking before 21 years of age is 0.3125 = 31.25%.

4 0

2 years ago

Mrs kanja ,miss kanene and Mrs nyaga have to mark a form three contest for 160students .They take 5mins ,4mins and 12mins respec

oksano4ka [1.4K]

Answer:

300 minutes

2:00 p.m

Step-by-step explanation:

Given the following:

Time taken to mark a script :

Mrs Kanja = 5mins

Miss Kanene = 4mins

Mrs Nyaga = 12 mins

Number of scripts = 160

Start time = 9:00 a.m

Rate at which each of them mark:

Mrs Kanja = t / 5

Miss Kanene = t/4

Mrs Nyaga = t/12

Combined rate :

t/5 + t/4 + t/12 = 160

(12t + 15t + 5t) / 60 = 160

32t / 60 = 160

32t = 160 * 60

32t = 9600

t = 9600 / 32

t = 300 minutes

300 minutes = 300/60 = 5hrs

9:00 a.m + 5 hours = 2:00 p.m

3 0

3 years ago

If an integer greater than four is raised to the one half power, we are finding ....

tankabanditka [31]

In this case of your exercise you need to know that

4^(1/2) = sqrt(4)

hope this help you

5 0

3 years ago

BRAINLIESTTT ASAP! please answer