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3 years ago

PLEASE HELP!!!!!! TIMED QUESTION!!!! FIRST CORRECT ANSWER WILL GET BRAINLIEST....PLEASE ANSWER NOW!!!!

Mathematics

1 answer:

Margarita [4]3 years ago

6 0

Answer:

Option (3)

Step-by-step explanation:

From the picture attached,

Bar graph sketched shows the grades earned by the students in an exam.

Number of students who achieved the grade A = 17

Number of students who achieved grade B = 14

Number of students with grade C = 5

Number of students with grade D = 9

Total students who took the exam = 17 + 14 + 5 + 9 = 45

Option (1)

" $\frac{1}{5}$ of the students earned a C"

Fraction of students who earned C = $\frac{\text{Students who earned C}}{\text{Total students}}$

= $\frac{5}{45}$

= $\frac{1}{9}$

Therefore, this option is incorrect.

Option (2)

"3% more students earned an A then B"

Percentage of students who earned A = $\frac{\text{Students got A}}{\text{Total students who took the exam}}\times 100$

= $\frac{17}{45}\times 100$

= 37.78%

Percentage of students who earned B = $\frac{\text{Students got B}}{\text{Total students who took the exam}}\times 100$

= $\frac{14}{45}\times 100$

= 31.11%

Difference in percentage = 37.78 - 31.11

= 6.67%

Therefore, this option is not correct.

Option (3)

"20% of the students earned a D"

Percentage of students who earned D = $\frac{\text{Students got D}}{\text{Total students who took the exam}}\times 100$

= $\frac{9}{45}\times 100$

= 20%

Option (3) is the correct option.

Option (4)

" $\frac{1}{4}$ of the class earned a B"

Fraction of class who earned B = $\frac{\text{Students got B}}{\text{Total students who took the exam}}$

= $\frac{14}{45}$

Therefore, Option (4) is not correct.

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Michelle can fold 4 baskets of clothes in 54 minutes, while Ruby can fold 4 baskets of clothes in 108 minutes. How long will it

padilas [110]

Michelle can fold 4/54 baskets per minute = 8/108 baskets per minute.
Ruby can fold 4/108 baskets per minute.

Each minute Michelle and Ruby work together, they can fold
8/108 +4/108 = 12/108 = 1/9
of a basket of clothes. For 8 baskets of clothes, it will take them
(8 baskets)/(1/9 baskets/minute) = 72 minutes

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3 years ago

A company’s stock was selling at $25 a share a month later it was selling at $30 a share what is the percent increase

rjkz [21]

Answer:

20% increase

Step-by-step explanation:

To find the percent increase, you can divide the increase value by the original: 30/25 = 1.2 --> 120%. Next, since they ask for the percent of increase, you can subtract 1 or 100% from your answer which would give you a final answer of 20% increase.

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3 years ago

Explain how you know that 88 is a solution to the equation 18x=11 by completing the sentences: The word "solution" means . . . 8

koban [17]

Correct Question:

Explain how you know that 88 is a solution to the equation 1/8x =11 by completing the sentences:

The word "solution" means . . .

88 is a solution to 1/8x=11 because . . .

Answer/Step-by-step explanation:

✔️The word solution means the value of the unknown variable, x. This means, when the value of x is substituted into the equation, the equation becomes balance as the value on the left equals the value on the right.

✔️88 is a solution to ⅛x = 11 because:

if we substitute x for 88 into the equation, both sides would be equal.

Thus:

⅛×88 = 11

11 = 11

6 0

3 years ago

Find Distance (4,6) (-4,-3)

vampirchik [111]

Answer:

$\sqrt{145}$

Step-by-step explanation:

The distance formula states that the distance between two points $(a,b)$ and $(c,d)$ is $\sqrt{(a-c)^2+(b-d)^2}$ .

The two points we have are $(4,6)$ and $(-4,-3)$ . Plugging these numbers into the distance formula, we have

$\sqrt{(4-(-4))^2+(6-(-3))^2$ .

Simplifying with order of operations, first using the distributive property, gives

$\sqrt{(4+4)^2+(6+3)^2$ .

Squaring and adding gives

$\sqrt{(4+4)^2+(6+3)^2}=\sqrt{8^2+9^2}\\~~~~~~~~~~~~~~~~~~~~~~~~~~~~=\sqrt{64+81}\\~~~~~~~~~~~~~~~~~~~~~~~~~~~~=\boxed{\sqrt{145}},$

which is the answer in simplest form. This also rounds to about 12.04.

7 0

2 years ago

Is it true that the planes x + 2y − 2z = 7 and x + 2y − 2z = −5 are two units away from the plane x + 2y − 2z = 1?

zhuklara [117]

Lets Find It Out..

First we'll find the equation of ALL planes parallel to the original one.

As a model consider this lesson:

Equation of a plane parallel to other

The normal vector is:
→n=<1,2−2>

The equation of the plane parallel to the original one passing through P(x0,y0,z0)is:

→n⋅< x−x0,y−y0,z−z0>=0
<1,2,−2>⋅<x−x0,y−y0,z−z0>=0
x−x0+2y−2y0−2z+2z0=0
x+2y−2z−x0−2y0+2z0=0

x+2y−2z+d=0 [1]
where a=1, b=2, c=−2 and d=−x0−2y0+2z0

Now we'll find planes that obey the previous formula and at a distance of 2 units from a point in the original plane. (We should expect 2 results, one for each half-space delimited by the original plane.)
As a model consider this lesson:

Distance between 2 parallel planes

In the original plane let's choose a point.
For instance, when x=0 and y=0:
x+2y−2z=1 => 0+2⋅0−2z=1 => z=−12
→P1(0,0,−12)

In the formula of the distance between a point and a plane (not any plane but a plane parallel to the original one, equation [1] ), keeping D=2, and d as d itself, we get:

D=|ax1+by1+cz1+d|√a2+b2+c2
2=∣∣1⋅0+2⋅0+(−2)⋅(−12)+d∣∣√1+4+4
|d+1|=2⋅3 => |d+1|=6First solution:
d+1=6 => d=5
→x+2y−2z+5=0Second solution:
d+1=−6 => d=−7
→x+2y−2z−7=0

8 0

3 years ago