Ask question

Ask question

All categories

3 years ago

8

tina puts the letters of the word RADAR on pieces of paper and puts the pieces in a bag she draws two letters without looking th

e first piece of paper is not replaced before the second piece is drawn what is the probability that tina draws an R twice?

2 answers:

Sloan [31]3 years ago

7 0

The answer to this question is: 1/10

Do 2/5 * 1/4 = 2/20 -> 1/10

Alona [7]3 years ago

3 0

The probability of the first pull is $\frac{1}{5}$
The probability of the second pull is $\frac{1}{4}$

You might be interested in

Is 3,540 reasonable for the difference 9,760-5,220

Ugo [173]

Answer:

no it's 4540

Step-by-step explanation:

you just subtract 5220 from 9760 and you get your difference

3 0

3 years ago

Which is the equation in slope-intercept form for the line that passes through (3, 7)

quester [9]

Answer:

$y = - \frac{5}{3} x + 12$

Step-by-step explanation:

First, rewrite the given equation in the form of y=mx+c.

m is the gradient while c is the y-intercept.

3x-5y=8

5y= 3x -8

$y = \frac{3}{5} x - \frac{8}{5}$

Thus, the gradient of the given equation is ⅗.

The product of the gradients of perpendicular lines is -1.

(gradient of line)(⅗) = -1

gradient of line= -1 ÷⅗

gradient of line= $- \frac{5}{3}$

$y = - \frac{5}{3} x + c$

To find the value of c, substitute a coordinate.

When x=3, y=7,

$7 = - \frac{5}{3} (3) + c$

7= -5 +c

c= 7+5

c= 12

Hence, the equation of the line is $y = - \frac{5}{3} x + 12$ .

6 0

3 years ago

We are studying the proportion of cities that have private garbage collector. We want a maximum error of 0.10 and a 95% confiden

True [87]

Answer:

The minimum number of cities we need to contact is 96.

Step-by-step explanation:

In a sample with a number n of people surveyed with a probability of a success of $\pi$ , and a confidence interval $1-\alpha$ , we have the following confidence interval of proportions.

$\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}$

In which

Z is the zscore that has a pvalue of $1 - \frac{\alpha}{2}$ .

The margin of error is:

$M = z\sqrt{\frac{\pi(1-\pi)}{n}}$

95% confidence interval

So $\alpha = 0.05$ , z is the value of Z that has a pvalue of $1 - \frac{0.05}{2} = 0.975$ , so $Z = 1.96$ .

In this problem, we have that:

$p = 0.5, M = 0.1$

$M = z\sqrt{\frac{\pi(1-\pi)}{n}}$

$0.1 = 1.96*\sqrt{\frac{0.5*0.5}{n}}$

$0.1\sqrt{n} = 0.98$

$\sqrt{n} = 9.8$

$(\sqrt{n})^{2} = (9.8)^{2}$

$n = 96$

The minimum number of cities we need to contact is 96.

8 0

3 years ago

Factor 125x^3-1000. Show your work.

Salsk061 [2.6K]

The left term is (5x)³.

The right term is 10³.

So, you can use the formula for the factorization of the difference of cubes.

... a³ - b³ = (a-b)(a² +ab +b²)

Here, you have a=5x, b=10, so the factorization is

... 125x³ -1000 = (5x-10)(25x² +50x +100)

4 0

3 years ago

The mass of an electron is approximately 9 × 10-28 grams, while the mass of a neutron is approximately 2 × 10-24 grams. Which of

aalyn [17]

Answer: the mass of a neutron is approximately 2,000 times the mass of an electron

Step-by-step explanation:

- the easiest way to solve this (in my opinion) is to simply divide the mass of a neutron by the mass of an electron

- $2 x10^{-24} / (9 x10^{-28} )$

= $(2/9) x10^{-24--28}$

= $(2/9)x10^{-24+28}$

≈ $0.2222x10^{28-24}$

≈ $0.2222x10^{4}$

≈ which is approximately 2222

- so 2222 is approximately 2000 times

- therefore, the mass of a neutron is approximately 2,000 times the mass of an electron

hope this helps :)

4 0

2 years ago

Read 2 more answers