Given the system of the following two linear equations:

A jar contains 8 red marbles numbered 1 to 8 and 7 blue marbles numbered 1 to 7. A marble is drawn at random from the jar. Find

Shkiper50 [21]

Answer:

Therefore the probability that the marble is blue or even numbered is $\frac{11}{15}$

Step-by-step explanation:

Probability: The ratio of favorable outcomes to the total outcomes.

It is denoted by P.

$Probability= \frac{\textrm{favorable outcomes}}{\textrm{Total outcomes}}$

Given that a jar contains 8 red marbles and 7 blue marbles.

Total number of marbles = (8+7) = 15

Let A = Event of getting a blue marble

B= Event of getting of even marble.

Even number blue marbles are 2, 4,6

Even number red marbles are 2, 4,6,8

The number of even marbles are =(3+4)=7

The probability of getting a blue marble is P(A)

$=\frac{\textrm{Total number of blue marbles}}{\textrm{Total number of blue marbles}}$

$=\frac{7}{15}$

The probability of getting a even marble is P(B)

$=\frac{\textrm{The number of even number marbles}}{\textrm{Total number of marbles}}$

$=\frac{7}{15}$

The probability of getting a even numbered blue marble P(A∩B)

$=\frac{3}{16}$

P(blue marble or even- numbered)

=P(A∪B)

=P(A)+P(B)-P(A∩B)

$=\frac{7}{15} +\frac{7}{15}-\frac{3}{15}$

$=\frac{11}{15}$

Therefore the probability that the marble is blue or even numbered is $\frac{11}{15}$

3 0

4 years ago

The time needed to complete a final examination in a particular college course is normallydistributed with a mean of 80 minutes

Artist 52 [7]

Answer:

a) 0.023

b) 0.286

c) 10 students will be unable to complete the exam inthe allotted time.

Step-by-step explanation:

We are given the following information in the question:

Mean, μ = 80 minutes

Standard Deviation, σ = 10 minutes

We are given that the distribution of time to complete an exam is a bell shaped distribution that is a normal distribution.

Formula:

$z_{score} = \displaystyle\frac{x-\mu}{\sigma}$

a) P(completing the exam in one hour or less)

P(x < 60)

$P( x < 60) = P( z < \displaystyle\frac{60 - 80}{10}) = P(z < -2)$

Calculation the value from standard normal z table, we have,

$P(x < 60) =0.023= 2.3\%$

b) P(complete the exam in more than 60 minutes but less than 75 minutes)

$P(60 \leq x \leq 75) = P(\displaystyle\frac{60 - 80}{10} \leq z \leq \displaystyle\frac{75-80}{10}) = P(-2 \leq z \leq -0.5)\\\\= P(z \leq -0.5) - P(z < -2)\\= 0.309- 0.023 = 0.286= 28.6\%$

c) P(completing the exam in more than 90 minutes)

P(x > 90)

$P( x > 90) = P( z > \displaystyle\frac{90 -80}{10}) = P(z > 1)$

$= 1 - P(z \leq 1)$

Calculation the value from standard normal z table, we have,

$P(x > 90) = 1 - 0.8413 = 0.1587 = 15.87\%$

15.87% of children of class will require more than 90 minutes to complete the test.

Number of children =

$\dfrac{15.87}{100}\times 60 = 9.52\approx 10$

Approximately, 10 students of class will require more than 90 minutes to complete the test.

4 0

4 years ago

What is between 3.25 and 3.26

Charra [1.4K]

Answer:

3.251, 3.252, 3.253, 3.254, 3.255.......3.259

Step-by-step explanation:

7 0

3 years ago

Read 2 more answers

How would I solve these problems?

oksian1 [2.3K]

You add the whole numbers together first and then you do the numerators then the denominators. Like for example, #2 would be 2 and then 4 on the top and 6 on the bottom since they share a common denominator! Hoped this helps.

3 0

3 years ago

What is the volume of a figure that is 2 inches wide,9 inches tall and 8 inches long?

Anvisha [2.4K]

Answer:

144inches cube

v=2*9*8cube

v=144 inche cube

4 0

3 years ago