A son is A years old. His father is B times older. How old was the father when the son was born?

Richard has just been given an l0-question multiple-choice quiz in his history class. Each question has five answers, of which o

myrzilka [38]

Answer:

a) 0.0000001024 probability that he will answer all questions correctly.

b) 0.1074 = 10.74% probability that he will answer all questions incorrectly

c) 0.8926 = 89.26% probability that he will answer at least one of the questions correctly.

d) 0.0328 = 3.28% probability that Richard will answer at least half the questions correctly

Step-by-step explanation:

For each question, there are only two possible outcomes. Either he answers it correctly, or he does not. The probability of answering a question correctly is independent of any other question. 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.

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

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.

Each question has five answers, of which only one is correct

This means that the probability of correctly answering a question guessing is $p = \frac{1}{5} = 0.2$

10 questions.

This means that $n = 10$

A) What is the probability that he will answer all questions correctly?

This is $P(X = 10)$

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

$P(X = 10) = C_{10,10}.(0.2)^{10}.(0.8)^{0} = 0.0000001024$

0.0000001024 probability that he will answer all questions correctly.

B) What is the probability that he will answer all questions incorrectly?

None correctly, so $P(X = 0)$

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

$P(X = 0) = C_{10,0}.(0.2)^{0}.(0.8)^{10} = 0.1074$

0.1074 = 10.74% probability that he will answer all questions incorrectly

C) What is the probability that he will answer at least one of the questions correctly?

This is

$P(X \geq 1) = 1 - P(X = 0)$

Since $P(X = 0) = 0.1074$ , from item b.

$P(X \geq 1) = 1 - 0.1074 = 0.8926$

0.8926 = 89.26% probability that he will answer at least one of the questions correctly.

D) What is the probability that Richard will answer at least half the questions correctly?

This is

$P(X \geq 5) = P(X = 5) + P(X = 6) + P(X = 7) + P(X = 8) + P(X = 9) + P(X = 10)$

In which

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

$P(X = 5) = C_{10,5}.(0.2)^{5}.(0.8)^{5} = 0.0264$

$P(X = 6) = C_{10,6}.(0.2)^{6}.(0.8)^{4} = 0.0055$

$P(X = 7) = C_{10,7}.(0.2)^{7}.(0.8)^{3} = 0.0008$

$P(X = 8) = C_{10,8}.(0.2)^{8}.(0.8)^{2} = 0.0001$

$P(X = 9) = C_{10,9}.(0.2)^{9}.(0.8)^{1} \approx 0$

$P(X = 10) = C_{10,10}.(0.2)^{10}.(0.8)^{0} \approx 0$

So

$P(X \geq 5) = P(X = 5) + P(X = 6) + P(X = 7) + P(X = 8) + P(X = 9) + P(X = 10) = 0.0264 + 0.0055 + 0.0008 + 0.0001 + 0 + 0 = 0.0328$

0.0328 = 3.28% probability that Richard will answer at least half the questions correctly

8 0

3 years ago

Can someone help me solve this? Pls and ty!

Zanzabum

Answer:

H. 95°

Step-by-step explanation:

m∠BGC is 10° smaller than m∠CGD, which means that m∠BGC is x° - 10°

m∠DGE is 25° more than m∠EGF, which means that m∠DGE is x° + 25°

The sum of all angles in a placement like this will always equal 360°

So we put all the measures of all angles on one side of thee equation and set it equal to 360*

x° + x° - 10° + 2x° + 25° + 2x° + 3x° + 30° = 360°

After combining like terms we get 9x° + 45° = 360°

After some algebra we get x = 35°

Now at the start we said that m∠DGE is x + 25°

Plug in 35° for x and we get 35° + 25°

The final answer is m∠DGE = 95°

Edit: Sorry if my answer looks a bit confusing. This is actually my first answer on Brainly so I'm quite new to this experience.

5 0

2 years ago

Read 2 more answers

Larry Calanan has earnings of S518 in a week. He is single and claims 2 withholding allowances. His deductions include FICA, Med

qaws [65]

Answer:

$482

Step-by-step explanation:

Data provided:

Total earning per week = $518

Medicare, federal withholding, state disability insurance, state withholding, union dues = $15

charitable contributions = $21

Now,

The total deductions = $15 + $21 = $36

also,

Net pay = Total income - Total deductions

thus,

Net pay = $518 - $36

or

Net Pat = $482

3 0

3 years ago

Find the product (4x-3) (3x+8)

m_a_m_a [10]

Hi there!

Assuming "Find the product" means multiplying (4x-3) by (3x+8) and factor to it's simplest form the answer would be:

12x²+23x-24

The way you solve this is by using the distributive property of multiplication as shown below:

Start by multiplying -3 from (4x-3) by everything in (3x+8)

3x*(-3) = -9x

8*(-3) = -24

Once you've done that you then multiply everything 4x

4x*8 = 32x

4x*3x = 12x²

(Note: when multiplying two of the same variables like x it means you are multiplying x by itself which is the same as x²)

When you put all of this together it looks like this

12x²+32x-9x-24

from there we combine like terms

32x-9x = 23x

to get

12x²+23x-24

I hope this helps!

God bless,

ASIAX

4 0

3 years ago

A fair coin is flipped 50 times

inna [77]

1/2 so that would be about 25 times heads show.

8 0

3 years ago