Ask question

Ask question

All categories

2 years ago

5

In a science test devi scores 15 marks more than lixin . If devi obtains twice as many marks as lexin . Find the number of marks

lixin obtains.

1 answer:

Aleks04 [339]2 years ago

7 0

Answer:

15

Step-by-step explanation:

D=2l

D=l+15

Substitute

2l=l+15

L=15

You might be interested in

A group of friends has gotten very competitive with their board game nights. They have found that overall, they each have won an

Amanda [17]

Answer: $\mu_x=18\text{ hours}$

$\sigma_x=4\text{ hours}$

Step-by-step explanation:

We know that mean and standard deviation of sampling distribution is given by :-

$\mu_x=\mu$

$\sigma_x=\dfrac{\sigma}{\sqrt{n}}$

, where $\mu$ = population mean

$\sigma$ =Population standard deviation.

n= sample size .

In the given situation, we have

$\mu=18\text{ hours}$

$\sigma=6\text{ hours}$

n= 2

Then, the expected mean and the standard deviation of the sampling distribution will be :_

$\mu_x=\mu=18\text{ hours}$

$\sigma_x=\dfrac{\sigma}{\sqrt{n}}=\dfrac{6}{\sqrt{2}}=4.24264068712\approx4$ [Rounded to the nearest whole number]

Hence, the the expected mean and the standard deviation of the sampling distribution :

$\mu_x=18\text{ hours}$

$\sigma_x=4\text{ hours}$

7 0

2 years ago

Based on a poll, 67% of Internet users are more careful about personal information when using a public Wi-Fi hotspot. What is

daser333 [38]

Answer:

The required probability is 0.988.

Step-by-step explanation:

Consider the provided information.

Based on a poll, 67% of Internet users are more careful about personal information when using a public Wi-Fi hotspot.

That means the probability of more careful is 0.67

The probability of not careful is: 1-0.67 = 0.33

We have selected four random Internet users. we need to find the probability that at least one is more careful about personal information.

P(At least one careful) = 1 - P(None of them careful)

P(At least one careful) = 1 - (0.33×0.33×0.33×0.33)

P(At least one careful) = 1 - 0.012

P(At least one careful) = 0.988

Hence, the required probability is 0.988.

The result may be higher because of the convenience bias in retrieving the sample. Because the survey subjects volunteered to respond not random.

3 0

2 years ago

Yolanda dug a hole in the ground that is deeper than -10 inches . She says the depth of the hole is greater than 10 inches. Is Y

denpristay [2]

No, she is not right

8 0

2 years ago

Casey needed to move 23 huge boxes from his truck to the loading dock. His forklift could only hold three boxes at once. How man

miss Akunina [59]

Answer:

8

Step-by-step explanation:

Since the forklift has a maximum capacity of three boxes per trip, simply divide the total number of boxes (23 boxes) by three and round up to the nearest whole unit to find the number of trips required:

$n=\frac{23}{3}=7.667$

Casey had to visit the dock 8 times. He moved three boxes in seven trips and two boxes in one trip.

6 0

2 years ago

A baker uses 13 1/2 cups of flour to make bread. She uses 2 1/4 cups of flour to make each loaf. The baker sells 2/3 of the loav

ollegr [7]

Answer:

She sells 4 loaves of bread

Step-by-step explanation:

Lets explain how to solve the problem

→ A baker uses $13\frac{1}{2}$ cups of flour to make bread

→ She uses $2\frac{1}{4}$ cups of flour to make each loaf

From these information we can find the number of loaves of bread

she can make

∵ There are $13\frac{1}{2}$ cups of flour

∵ Each loaf of bread needs $2\frac{1}{4}$ cups of flour

∴ The number of loaves = $13\frac{1}{2}$ ÷ $2\frac{1}{4}$

To divide two mixed numbers make them improper fractions and

change the division sign to multiplication sign and reciprocal the

fraction after the division sign

∵ $13\frac{1}{2}$ = $\frac{(13)(2)+1}{2}$

∴ $13\frac{1}{2}$ = $\frac{27}{2}$

∵ $2\frac{1}{4}$ = $\frac{(2)(4)+1}{4}$

∴ $2\frac{1}{4}$ = $\frac{9}{4}$

∴ The number of loaves = $\frac{27}{2}$ × $\frac{4}{9}$

∴ The number of loaves = 6

<em>She can make 6 loaves</em>

→ The baker sells $\frac{2}{3}$ of the loaves of bread that she makes

→ We need to find the number of loves of bread she sells

∵ She sells $\frac{2}{3}$ of the loaves

∵ There are 6 loves

∴ The number of loaves she sells = 6 × $\frac{2}{3}$ = 4

<em>She sells 4 loaves of bread</em>

7 0

2 years ago