1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
mario62 [17]
4 years ago
7

A box contains 2 red marbles, 3 green marbles, and 3 blue marbles. if we choose a marble, then another marble without putting th

e first one back in the box, what is the probability that the first marble will be green and the second will be blue?
Mathematics
2 answers:
Bad White [126]4 years ago
7 0
There are 7 marbles, including 3 green ones, so at the start, there is a 3/7 chance of getting a green marble.
Assuming you did get a green one, there are now 6 marbles left, with 2 blue marbles, so there is a 2/6 chance of taking a blue marble.
Given that both have to happen, you must multiply each probability, hence the total probability is 3/7 x 2/6, or a 1/7 chance.
Hope this helped
Zepler [3.9K]4 years ago
4 0

Answer:

The answer is actually 9/56

Step-by-step explanation:


You might be interested in
Question 2 of 10
svet-max [94.6K]
4x4=16
5x5=25
2x2=4
The question simplifies to 4*5/2=10
8 0
3 years ago
There are n questions on a multiple choice exam, and for each question, there are four choices. To pass the exam, one must corre
irinina [24]

Answer:

a) 0.352% probability of the student passing

b) 5

c) 1.875

Step-by-step explanation:

For each question, there are only two possible outcomes. Either the student answers it correctly, or he answers it wrong. The probability of correctly answering a question is independent from the probability of correctly answering other questions. So 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.

The expected value of the binomial distribution is:

E(X) = np

The variance of the binomial distribution is:

V(X) = np(1-p)

For each question, there are four choices.

One choice is correct, so p = \frac{1}{4} = 0.25

a. Find the probability of the student passing for n = 10.

0.7*10 = 7

This is P(X \geq 7) when n = 10

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

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

P(X = 7) = C_{10,7}.(0.25)^{7}.(0.75)^{3} = 0.0031

P(X = 8) = C_{10,8}.(0.25)^{8}.(0.75)^{2} = 0.0004

P(X = 9) = C_{10,9}.(0.25)^{9}.(0.75)^{1} = 0.00002

P(X = 10) = C_{10,10}.(0.25)^{10}.(0.75)^{0} \cong 0

P(X \geq 7) = P(X = 7) + P(X = 8) + P(X = 9) + P(X = 10) = 0.0031 + 0.0004 + 0.00002 = 0.00352

0.352% probability of the student passing

b. Find the expected number of questions answered correctly for n = 20.

Here we have n = 20. So

E(X) = np = 20*0.25 = 5

c. Find the variance for the number of questions answered correctly for n = 10.

Here we have n = 10.

V(X) = np(1-p) = 10*0.25*0.75 = 1.875

5 0
4 years ago
The top of the rectangular box is 15 cm by 20 cm and its hight is 4 cm. And ant begins at one corner of the box and walks along
Nimfa-mama [501]

Answer:

92 cm

Step-by-step explanation:

Look at the attached photo, it may give you a better understanding

As we know it touches all 8 corners so the shortest distance in cm that the ant may travel is:

15+ 4+15+4 +20 + 15 +15 + 4 = 92 cm

8 0
3 years ago
15 boys can cut the grass on the football field in 12days. how many days will it take 9 boys​
Inessa [10]
X=15-12
X=3(number of days in difference to the number of people)
X=9-3
X=6 it would take 6 days to cut the grass with 9 boys
5 0
3 years ago
HELP!! It’s question 8
Flauer [41]

Answer:

the answer is 1.25 or 5/4

4 0
3 years ago
Read 2 more answers
Other questions:
  • A picture is 3 in. wide by 5 in. high was enlarged so that the width was 15 inches. how high is the enlarged picture>
    7·1 answer
  • I do not understand how to transfer standard form into slope intercept form or point slope form or how to do it reverse.
    7·1 answer
  • The surface area of the cube is 54 square feet. What is the length, in feet, of one edge of the cube?​
    9·1 answer
  • A train leaves Zurich at 2240 and arrives in Paris at 0732. work out the time taken​
    14·1 answer
  • What is one whole minus 3/8
    11·2 answers
  • If y=x+2 changed to y=x-1 how would it change
    13·1 answer
  • If angles A and Bare alternate interior angles, what is the measure of angle B
    8·1 answer
  • AYO SOMONE HELP ME PLZ
    7·1 answer
  • I cant decide if its b or d please help for brainlist !!!!!!!!!!!!!
    15·2 answers
  • What is the value of x for the regular polygon shown below?<br> 2x + 4<br> 36
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!