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
Otrada [13]
3 years ago
10

An urn contains 3 red and 7 black balls. Players A and B take turns (A goes first) withdrawing balls from the urn consecutively.

What is the probability that A selects the first red ball? Express your answer as a decimal rounded to the next hundredth, e.g. 0.24 for 0.23932
Mathematics
1 answer:
andrey2020 [161]3 years ago
6 0

Answer:

The probability that A selects the first red ball is 0.5833.

Step-by-step explanation:

Given : An urn contains 3 red and 7 black balls. Players A and B take turns (A goes first) withdrawing balls from the urn consecutively.

To find : What is the probability that A selects the first red ball?

Solution :

A wins if the first red ball is drawn 1st,3rd,5th or 7th.

A red ball drawn first, there are E(1)= ^9C_2 places in which the other 2 red balls can be placed.

A red ball drawn third, there are E(3)= ^7C_2 places in which the other 2 red balls can be placed.

A red ball drawn fifth, there are E(5)= ^5C_2 places in which the other 2 red balls can be placed.

A red ball drawn seventh, there are E(7)= ^3C_2 places in which the other 2 red balls can be placed.

The total number of total event is S= ^{10}C_3

The probability that A selects the first red ball is

P(A \text{wins})=\frac{(^9C_2)+(^7C_2)+(^5C_2)+(^3C_2)}{^{10}C_3}

P(A \text{wins})=\frac{36+21+10+3}{120}

P(A \text{wins})=\frac{70}{120}

P(A \text{wins})=0.5833

You might be interested in
Simplifying the following expression:<br> 6x + 2(3x + 5) + (-9)
Nezavi [6.7K]
= <span>6x + 2(3x + 5) + (-9)
= 6x +6x + 10 - 9
= 12x + 1

In short, Your Final Answer would be 12x + 1

Hope this helps!</span>
3 0
3 years ago
Read 2 more answers
A bus covers a distance of 90km at a uniform speed. Had the speed been 15km/hour it would have taken 30 minutes less for the jou
Brrunno [24]

Answer:

Step-by-step explanation

Let's say d = distance, r = speed and t = time

We know the distance formula is :

distance = speed x time

d = r multiplied by t

d = rt

If the speed is 15km/hr, the time would be 30 minutes shorter.

Since d = rt,

90 = 15t

t = 6,

This means the time taken for the bus to complete the journey at 15km/hr would be 6hrs.

Originally though, the journey takes 30 minutes longer.

So we can say t = 6.5 hrs , and we know d = 90

Now we use the distance formula:

d = rt, since we want to find the original speed, we want to find r.

Speed = distance/time

r = d/t

r = 90/6.5

r = 180/13

Therefore the original speed is 180/13 km/hr

4 0
3 years ago
The question is:
saul85 [17]
f(x) = \sqrt{x+1} \\ y = \sqrt{x+1} \ or \ y^2 = x+1 \ or \ x = y^2 - 1 \\ Therefore, \ f^{-1}(x)=x^2 - 1

(fof^{-1})(a) = f(f^{-1}(a))=f(a^2-1) \\ =\sqrt{a^2-1+1}=\sqrt{a^2}=a \\  \\ (f^{-1}of)(a)=f^{-1}(f(a))=f^{-1}(\sqrt{a+1})= \\ (\sqrt{a+1})^2-1 = a+1-1 = a

Therefore, (fof^{-1})(a) = (f^{-1}of)(a) = a

8 0
2 years ago
toni can carry 15 lb in her backpack.her lunch weighs 1 lb, her gym clothes weigh 2 lb ,and her books weigh 3lb each. how many b
MakcuM [25]

15-3=12

12/3=4

4 books

6 0
3 years ago
Three times the sum of a number and 18 and is at least -30
miss Akunina [59]

Answer:

im sry i need hte points

Step-by-step explanation:

5 0
2 years ago
Read 2 more answers
Other questions:
  • Factor each expression 36abc +54ad
    15·1 answer
  • Circle the numbers that are integers <br>5 --4 2.6 0.8 repeating and 100​
    13·2 answers
  • 3. The positive root of 154 is located between which two consecutive integer values?
    6·2 answers
  • What is 4 2/5 × 1 1/2 ​
    7·2 answers
  • Evaluate 3 to the 2nd power plus 7 times 2
    10·2 answers
  • Please hurry due today
    11·1 answer
  • If you solve the equation for ax+by/c=d for x, what would you get?
    6·1 answer
  • What is the degree of the monomial -9x^4?
    7·1 answer
  • Srekar needs to increase the size of the prism below by 2 inches on each side. The original prism has a length of 3, a depth of
    9·1 answer
  • Which algebraic expression is equivalent to this expression.3(2x-8)-11xA. -5x-24B. -17X -24C. -5X -8Please help I will mark you
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!