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
iren [92.7K]
3 years ago
13

The numbers​ 1, 2,​ 3, 4, and 5 are written on slips of​ paper, and 2 slips are drawn at random one at a time without replacemen

t. ​(a) Find the probability that the first number is 4​, given that the sum is 9. ​(b) Find the probability that the first number is 3​, given that the sum is 8.
Mathematics
1 answer:
mamaluj [8]3 years ago
7 0
<h2>Answer:</h2>

(a)

The probability is :  1/2

(b)

The probability is :  1/2

<h2>Step-by-step explanation:</h2>

The numbers​ 1, 2,​ 3, 4, and 5 are written on slips of​ paper, and 2 slips are drawn at random one at a time without replacement.

The total combinations that are possible are:

(1,2)   (1,3)    (1,4)    (1,5)

(2,1)   (2,3)   (2,4)   (2,5)

(3,1)   (3,2)   (3,4)   (3,5)

(4,1)   (4,2)   (4,3)   (4,5)

(5,1)   (5,2)   (5,3)   (5,4)

i.e. the total outcomes are : 20

(a)

Let A denote the event that the first number is 4.

and B denote the event that the sum is: 9.

Let P denote the probability of an event.

We are asked to find:

               P(A|B)

We know that it could be calculated by using the formula:

P(A|B)=\dfrac{P(A\bigcap B)}{P(B)}

Hence, based on the data we have:

P(A\bigcap B)=\dfrac{1}{20}

( Since, out of a total of 20 outcomes there is just one outcome which comes in A∩B and it is:  (4,5) )

and

P(B)=\dfrac{2}{20}

( since, there are just two outcomes such that the sum is: 9

(4,5) and (5,4) )

Hence, we have:

P(A|B)=\dfrac{\dfrac{1}{20}}{\dfrac{2}{20}}\\\\i.e.\\\\P(A|B)=\dfrac{1}{2}

(b)

Let A denote the event that the first number is 3.

and B denote the event that the sum is: 8.

Let P denote the probability of an event.

We are asked to find:

               P(A|B)

Hence, based on the data we have:

P(A\bigcap B)=\dfrac{1}{20}

( since, the only outcome out of 20 outcomes is:  (3,5) )

and

P(B)=\dfrac{2}{20}

( since, there are just two outcomes such that the sum is: 8

(3,5) and (5,3) )

Hence, we have:

P(A|B)=\dfrac{\dfrac{1}{20}}{\dfrac{2}{20}}\\\\i.e.\\\\P(A|B)=\dfrac{1}{2}

You might be interested in
What is the value of f in the equation f+1/6=3/7
kari74 [83]
11/42
The way I got it is because I took 1/6 minus 3/7 to get the answer of f=11/42
4 0
3 years ago
Read 2 more answers
A teacher randomly chooses a two-person leadership team from a group of four qualified students. Three of the students, Sandra,
nata0808 [166]

Answer:

What is P(A), the probability that the first student is a girl? (3/4)

What is P(A), the probability that the first student is a girl? (3/4)What is P(B), the probability that the second student is a girl? (3/4)

What is P(A), the probability that the first student is a girl? (3/4)What is P(B), the probability that the second student is a girl? (3/4)What is P(A and B), the probability that the first student is a girl and the second student is a girl? (1/2)

The probability that the first student is a girl is (3/4), likewise for the 2nd 3rd and 4th it's still (3/4). The order you pick them doesn't matter.

However, once you're looking at P(A and B) then you're fixing the first position and saying if the first student is a girl what's the probability of the second student being a girl.

3 0
3 years ago
A source of laser light sends rays AB and AC toward two opposite walls of a hall. The light rays strike the walls at points B an
____ [38]

Answer: 70  meters.

Step-by-step explanation:

Observe the figure attached.

The distance between the walls is:

DE=AD+AE

<em />

Both triangles are right triangles. Therefore, you can calculate the distance  between the walls as following:

- Calculate the distance AD:

cos\alpha=\frac{adjacent}{hypotenuse}\\\\cos(60\°)=\frac{AD}{60}\\AD=30m

- Calculate the distance AE:

tan\beta =\frac{opposite}{adjacent}\\\\tan(45\°)=\frac{40}{AE}\\\\AE=\frac{40}{tan(45\°)}\\\\AE=40m

Therefore the distance between the walls is:

DE=30m+40m=70m

6 0
3 years ago
Read 2 more answers
One 16-ounce bottle of an energy drink has an average of 500 mg of caffeine with a standard deviation of 25 mg. In a carton cont
labwork [276]
<span>In this case, every bottle has 500 mg of caffeine with a standard deviation of 25 mg. The equation of a bottle will be: 500 +/- 25mg caffeine per bottle.

To calculate a carton containing 30 bottles, you just need the equation with 30. It will become: (500x30) +/- (25x30)mg= 15000 +/- 750 mg of caffeine per carton</span>
7 0
3 years ago
How many zeroes do we write when we write all the integers 1 to 243 in base 3?
Monica [59]

Answer:

289 numbers

Step-by-step explanation:

Above you will find the list of integers from 1 to 243 in base 3:

(1, 2, 10, 11, 12, 20, 21, 22, 100, 101, 102, 110, 111, 112, 120, 121, 122, 200, 201, 202, 210, 211, 212, 220, 221, 222, 1000, 1001, 1002, 1010, 1011, 1012, 1020, 1021, 1022, 1100, 1101, 1102, 1110, 1111, 1112, 1120, 1121, 1122, 1200, 1201, 1202, 1210, 1211, 1212, 1220, 1221, 1222, 2000, 2001, 2002, 2010, 2011, 2012, 2020, 2021, 2022, 2100, 2101, 2102, 2110, 2111, 2112, 2120, 2121, 2122, 2200, 2201, 2202, 2210, 2211, 2212, 2220, 2221, 2222, 10000, 10001, 10002, 10010, 10011, 10012, 10020, 10021, 10022, 10100, 10101, 10102, 10110, 10111, 10112, 10120, 10121, 10122, 10200, 10201, 10202, 10210, 10211, 10212, 10220, 10221, 10222, 11000, 11001, 11002, 11010, 11011, 11012, 11020, 11021, 11022, 11100, 11101, 11102, 11110, 11111, 11112, 11120, 11121, 11122, 11200, 11201, 11202, 11210, 11211, 11212, 11220, 11221, 11222, 12000, 12001, 12002, 12010, 12011, 12012, 12020, 12021, 12022, 12100, 12101, 12102, 12110, 12111, 12112, 12120, 12121, 12122, 12200, 12201, 12202, 12210, 12211, 12212, 12220, 12221, 12222, 20000, 20001, 20002, 20010, 20011, 20012, 20020, 20021, 20022, 20100, 20101, 20102, 20110, 20111, 20112, 20120, 20121, 20122, 20200, 20201, 20202, 20210, 20211, 20212, 20220, 20221, 20222, 21000, 21001, 21002, 21010, 21011, 21012, 21020, 21021, 21022, 21100, 21101, 21102, 21110, 21111, 21112, 21120, 21121, 21122, 21200, 21201, 21202, 21210, 21211, 21212, 21220, 21221, 21222, 22000, 22001, 22002, 22010, 22011, 22012, 22020, 22021, 22022, 22100, 22101, 22102, 22110, 22111, 22112, 22120, 22121, 22122, 22200, 22201, 22202, 22210, 22211, 22212, 22220, 22221, 22222, 100000)

If you count them, you will find that there are 289 numbers in total!

8 0
3 years ago
Other questions:
  • A recipe for French toast that serves 6 calls for 3/4 cup granulated sugar , one cup of evaporated milk ,3/4 teaspoon of vanilla
    10·1 answer
  • I need to know how to do the problem
    9·1 answer
  • What is the equation of the plane that contains the triangle shown in the diagram *answers in question*
    10·2 answers
  • Given: angle 2 and angle 4 are vertical. Prove angle 2 congruent to angle 4
    13·2 answers
  • A ball is thrown into the air with an upward velocity of 80ft/s. Its height H in feet after T seconds id given by the function H
    8·1 answer
  • I need help on this question plz
    10·1 answer
  • Does this sample have a bias
    15·1 answer
  • Find an equation of the line parallel to the line 3x + 6y = 5 and passing through the point (1 , 3). Write the equation in the s
    10·1 answer
  • Carlos recorded the weight of several bags of potatoes. He then counted the number of potatoes in each bag. The scatterplot belo
    11·2 answers
  • Plz help<br> Will be marked BRAINLIEST!!!!!!
    11·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!