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2 years ago

Assessment: Solve Me!

Mathematics

1 answer:

Arte-miy333 [17]2 years ago

5 0

Answer:

1 . option b

2. option d

Step-by-step explanation:

1) Diameter = 8cm

Radius = 8/2 = 4cm

2) Diameter = 8cm

Radius = 4cm

$Volume = \frac{1}{3} \pi r^2h = \frac{1}{3} \pi 4^2 \times 15 = 16 \pi \times 5 = 80 \pi = 251.2cm^3$

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3x(x+30°) i really need help asap

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A13x2+390x here is the answer

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3 years ago

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Barbara made a bad investment. Rather than earning interest, her money is decreasing in value by 11% each week! After just one w

pochemuha

Answer: She started with $160.

It will take 6 weeks before she has less than half of what she originally invested.

Step-by-step explanation:

If her money is decreasing in value by 11% each week, it means that the rate at which it is decreasing is exponential.

We would apply the formula for exponential decay which is expressed as

A = P(1 - r)^t

Where

A represents the value of the investment after t weeks.

t represents the number of weeks.

P represents the initial value of the investment.

r represents rate of depreciation.

From the information given,

A = $142.40

r = 11% = 11/100 = 0.11

t = 1

Therefore

142.40 = P(1 - 0.11)^1

142.40 = P(0.89)

P = 142.4/0.89

P = 160

For her to have half of what she invested originally, then

80 = 160(0.89)^t

80/160 = (0.89)^t

0.5 = (0.89)^t

Taking log of both sides to base 10

Log 0.5 = log0.89^t = tlog0.89

- 0.3010 = - 0.051t

t = - 0.3010/- 0.051

t = 5.9

Approximately 6 weeks

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3 years ago

The mean of four numbers is 9 what is the total of the four numbers?

BigorU [14]

Answer:

Step-by-step explanation:

36/4 = 9 wish this helps!

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3 years ago

The perimeter of a rectangle is 30.8 km and it’s diagonal length is 11 km. Find it’s length and width

blsea [12.9K]

Answer:

Length of the rectangle is 15.0325 km and width is 0.3765 km.

Explanation:

Given:

Perimeter of a rectangle = 30.8 km

Length of diagonal of rectangle = 11 km

To find:

The length and width of rectangle=?

Solution:

Lets assume length of the rectangle = x km

And assume width of the rectangle = y km

Lets first create equation using given perimeter

perimeter of rectangle = 2 ( length + width )

=> 30.8 km = 2 ( x + y )

=> $x + y = \frac{30.8}{2}$

=> y = 15.4 – x ------(1)

As diagonal and two sides of rectangle forms right angle triangle whose hypoteneus is diagonal ,

=> $length^2 + width^2 = diagonal^2$

=> $x^2 + y^2 = 11^2$

=> $x^2 + y^2 = 121$

On substituting value of y from (1) in above equation we get

=> $x^2 + (15.4-x)^2 = 121$

=> $x^2 + (15.4)^2 + x^2 – 2 x 15.4 \times x = 121$

=> $2x^2-30.8x + 237.16 -121 = 0$

=> $2x^2-30.8x + 116.16 = 0$

Solving above quadratic equation using quadratic formula

General form of quadratic equation is

$ax^2 +bx +c = 0$

And quadratic formula for getting roots of quadratic equation is

$x= \frac{ -b\pm\sqrt{(b^2-4ac)}}{2a}$

As equation is $2x^2-30.8x + 116.16 = 0$ , in our case

a = 2 , b = -30.8 and c = 116.16

Calculating roots of the equation we get

$x=\frac{ -(-30.8)\pm\sqrt{(-30.8)^2-4(2)( 11)} } {(2\times2)}$

$x=\frac{30.8\pm\sqrt{(948.64-88)}}{4}$

$x=\frac{30.8\pm\sqrt{860.64}}{4}$

$x=\frac{(30.8\pm29.33)}4$

$x=\frac{(30.8+29.33)}{4}$

$x=\frac{(30.8-29.33)}{4}$

=> x = 15.0325 or x = 0.3675

As generally length is longer one ,

So x = 1.0325

From equation (1) y = 15.4 – x = 0.3765

Hence length of the rectangle is 15.0325 km and width is 0.3765 km.

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3 years ago

Which of the answer choices could be the one missing data item for the following set, if the mode is 12?

crimeas [40]

Answer:

Step-by-step explanation:

first of all, what is mode: it is the highest occuring number in a set of numbers.

now since 12 is supposed to be the mean and it occurs twice but 9 also occurs twice so for 12 to be the mode, we must add one more 12.

therefore the answer is 12

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3 years ago

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