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
elena55 [62]
3 years ago
6

A bag contain 80 balls numbered 1,...,80. before the game starts, you choose 10 different numbers from among 1,..80 and write th

em on piece of paper. then 20 balls are selected with out replacement out of the bag at random.
a. What is the probability that all your numbers are selected?

b. What is the probability that none of your numbers is selected?

c. What is the probability that exactly 4 of your numbers are selected?
Mathematics
1 answer:
alekssr [168]3 years ago
8 0

Answer:

a. 0.24094

b. 0.2494

c. 0.1473

Step-by-step explanation:

The total probability of choosing any 20 random balls out of 80 is 80 \choose 20 \\. We use combination since the order of selection does not matter

a. P(all numbers are selected)

10 \choose 10 are our numbers, 70 \choose 10 is the selection of other ten numbers apart from our numbers.

\frac{{10\choose 10}{70 \choose 10}}{{80 \choose 20}} = 0.24094

b. P(none of them are selected)

Since none of our numbers are selected, we assume that all the numbers selected are from the other 70.

\frac{{70 \choose 20}}{{80 \choose 20}} = 0.2494

c. P (exactly four are selected)

Only four from our numbers are selected and the rest 16 from the other 70 numbers.

\frac{{10\choose 4}{70 \choose 16}}{{80 \choose 20}} = 0.1473

You might be interested in
Which triangle would be most helpful in finding the distance between the points (-4, 3) and (1,-2) on the coordinate
earnstyle [38]

Answer:

On a coordinate plane, a triangle has points (negative 4, 3), (negative 4, negative 2), (1, negative 2).

Step-by-step explanation:

The points (-4,3), (1,2) and (-4, -2) would form a right triangle when graphed and connected by lines.

(-4,3), (1,2) and (1,3) would also work as well

5 0
2 years ago
In the triangles, Line segment A C is-congruent-to line segment F E and Line segment B C is-congruent-to line segment D E. Trian
choli [55]

Answer:

Line segment A B is longer than Line segment F D. This is the correct statement from the given statements.

Step-by-step explanation:

Given:

In ΔABC and ΔFDE

Segment AC≅Segment FE

Segment BC≅Segment DE

∠BCA = 72° and ∠DEF = 65°

Now by the property of a Triangle we know that

Side opposite to the greater angle is longer than the side opposite to the smaller angle.

So, Side opposite to the greater angle (∠BCA = 72°) is AB and

The side opposite to the smaller angle (∠DEF = 65°) is FD.

Therefore, side AB is Longer than side FD.  

4 0
3 years ago
Suppose x is any positive number. Circle 1: center (0, 0) and radius 2x Circle 2: center (0, 0) and radius 10x Why is circle 1 s
Alexeev081 [22]

Answer:

Because both have the center of (0,0)

3 0
3 years ago
Graph the solution to the following system of inequalities in the coordinate plane.
Goshia [24]

Answer:

see below

Step-by-step explanation:

The first equation is in slope-intercept form, so you can see that the boundary line has a slope of -2 and goes through the point (x, y) = (0, -4). Since the comparison is "<", the line is dashed and shading is below it.

The second equation is that of a vertical boundary line at x=-3. It is solid, because the comparison includes the "equal" case. Shading is to the right of it, where x values are greater than -3.

4 0
4 years ago
A colony of bacteria is growing at a rate of 0.2 times its mass. Here time is measured in hours and mass in grams. The mass of t
11Alexandr11 [23.1K]

Answer:

  • <u>Question 1:</u>      dm/dt=0.2m<u />

<u />

  • <u>Question 2:</u>     m=Ae^{(0.2t)}<u />

<u />

  • <u>Question 3:</u>      m=10e^{(0.2t)}<u />

<u />

  • <u>Question 4:</u>      m=10g<u />

Explanation:

<u>Question 1: Write down the differential equation the mass of the bacteria, m, satisfies: m′= .2m</u>

<u></u>

a) By definition:  m'=dm/dt

b)  Given:  rate=0.2m

c) By substitution:  dm/dt=0.2m

<u>Question 2: Find the general solution of this equation. Use A as a constant of integration.</u>

a) <u>Separate variables</u>

     dm/m=0.2dt

b)<u> Integrate</u>

           \int dm/m=\int 0.2dt

            ln(m)=0.2t+C

c) <u>Antilogarithm</u>

       m=e^{0.2t+C}

       m=e^{0.2t}\cdot e^C

         e^C=A\\\\m=Ae^{(0.2t)}

<u>Question 3. Which particular solution matches the additional information?</u>

<u></u>

Use the measured rate of 4 grams per hour after 3 hours

            t=3hours,dm/dt=4g/h

First, find the mass at t = 3 hours

            dm/dt=0.2m\\\\4=0.2m\\\\m=4/0.2\\\\m=20g

Now substitute in the general solution of the differential equation, to find A:

          m=Ae^{(0.2t)}\\\\20=Ae^{(0.2\times 3)}\\\\A=20/e^{(0.6)}\\\\A=10.976

Round A to 1 significant figure:

  • A = 10.

<u>Particular solution:</u>

           

             m=10e^{(0.2t)}

<u>Question 4. What was the mass of the bacteria at time =0?</u>

Substitute t = 0 in the equation of the particular solution:

         m=10e^{0}\\\\m=10g

3 0
3 years ago
Other questions:
  • Find the number of possible 5-card hands that contain the cards specified from a standard 52-card deck.
    6·1 answer
  • What is 17 divided by 5,542
    8·2 answers
  • Solve the equation. 4d + 2d – 4d + 4 = 3d
    9·2 answers
  • Find the range of the sample data set.<br><br> 16,465 17,342 19,835 15,147 15,898 18,324
    9·2 answers
  • Evaluate this equation: (4^-3) (4^6)
    11·2 answers
  • Suppose that A = {2, 4, 6}, B = {2, 6}, C = {4, 6}, and D = {4, 6, 8}. Identify the pairs of sets in which one is a subset of th
    9·2 answers
  • Which of the following is NOT equivalent to 240/300
    6·1 answer
  • What is nine less than twice a number
    6·1 answer
  • Out of 4,000 colleges surveyed, 60% reported that SAT scores were not used as a high consideration in viewing their applications
    12·1 answer
  • How do you find volume using V = BH
    9·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!