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3 years ago

9

A school assembly had 25 students in attendance, and 20% of them were first-graders. How many first-graders were at the assembly

?

1 answer:

artcher [175]3 years ago

5 0

Answer:

5

Step-by-step explanation:

20%=0.2

25 x 0.2 = 5

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A printer has a contract to print 100,000 posters for a political candidate. He can run the posters by using any number of plate

yulyashka [42]

Answer:

25

Step-by-step explanation:

From the given information;

Numbers of posters that can be printed in an hour = no of impression/hour × no of plate utilized in each impression.

= 1000x

Thus, the required number of hours it will take can be computed as:

$\implies \dfrac{100000}{1000x} \\ \\ =\dfrac{100}{x}$

cost per hour = 125

If each plate costs $20 to make, then the total number of plate will equal to 40x

∴

The total cost can be computed as:

$C(x) = (\dfrac{100}{x}) \times 125 + 20 x --- (1)$

$C'(x) = (-\dfrac{12500}{x^2}) + 20 --- (2)$

At C'(x) = 0

$\dfrac{12500}{x^2} = 20$

$\dfrac{12500}{20} = x^2$

$x^2= 625$

$x = \sqrt{625}$

x = 25

$C'' (x) = -12500 \times \dfrac{-2}{x^3} +0$

$C'' (x) = \dfrac{25000}{x^3}$

where; x = 25

$C'' (x) = \dfrac{25000}{25^3}$

C''(x) = 1.6

Thus, at x = 25, C'' > 0

As such, to minimize the cost, the printer needs to make 25 metal plates.

4 0

3 years ago

WILL MARK BRAINLIEST!!!!!

statuscvo [17]

The shape with a rotational symmetry would remain the same when rotated

The shape with the smallest angle of rotational symmetry of 180 degrees is shape D

<h3>How to determine the shape?</h3>

To do this, we simply examine each of the options

<u>Shape A: Cross</u>

The shape has 4 equal sides.

So, the smallest angle of rotational symmetry is:

Angle = 360/4

Angle = 90

The smallest angle of rotational symmetry is 90 degrees

<u>Shape B: Star</u>

The shape has 5 vertices.

So, the smallest angle of rotational symmetry is:

Angle = 360/5

Angle = 72

The smallest angle of rotational symmetry is 72 degrees

<u>Shape C: Composite figure</u>

This shape has a square and a triangle merged together at two ends

This means that the smallest angle of rotational symmetry is a complete rotation of 360 degrees

<u>Shape D: Circle</u>

The circle is divided into two equal segments.

The angle on the straight line of each segment is:

Angle = 360/2

Angle = 180

The smallest angle of rotational symmetry is 180 degrees

Hence, the shape with the smallest angle of rotational symmetry of 180 degrees is shape D

Read more about rotational symmetry at:

brainly.com/question/12214455

8 0

2 years ago

5. The dimensions, in inches, of a shipping box at We Ship 4 You can be expressed as width x, length x + 5, and height 3x - 1. T

meriva

The volume of a cuboid is given by length × width × height

We have:

Volume = 7.6 ft³
Height = 3x - 1
Length = x + 5
Width = x

Substituting these into the formula, we have:

7.6 = (3x - 1) (x + 5) (x)
7.6 = [3x² + 15x - x - 5] (x)
7.6 = [3x² + 14x - 5](x)
7.6 = 3x³ + 14x² - 5x
0 = 3x³ + 14x² - 5x - 7.6

Drawing the graph is one way of finding the solution (refer to the graph below):

We have three solutions (where the curve crosses the x-axis):
x = -4.9
x = -0.6
x = 0.8

Putting these solutions back into the context, since we are looking for the value of x which is part of measurement of length, we cannot have negative value, so we will take the value of x = 0.8 ft

Converting 0.8 ft into inches = 0.8 × 12 inches = 9.6 inches

Answer: x = 9.6 inches

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3 years ago

If Judy has 4 blouses and 5 skirts, how many different outfits of a blouse and skirt can she wear?

Aloiza [94]

Answer:

20

Step-by-step explanation:

i think but not fur shure

3 0

3 years ago

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Your friend is 5 years less then half her mom's age. your friend is 15 years old. how is the mother.

Digiron [165]

The mother is 25. i think

4 0

3 years ago

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