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Paha777 [63]
2 years ago
10

A student earns an 80% on their science test. If she got 20 questions correct, how many total were on the test?

Mathematics
1 answer:
galina1969 [7]2 years ago
5 0
25 questions
Explanation: 20 divided by 25 is .8 which is 80%
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You are purchasing a car for $12,465.00 plus 5.65% sales tax. You make a $1,300.00 down payment and have a fair credit score. If
pochemuha

Answer:

21.74

Step-by-step explanation:

4 0
2 years ago
VGravel is being dumped from a conveyor belt at a rate of 50 ft3/min. It forms a pile in the shape of a right circular cone whos
kupik [55]

Answer:

0.325 ft/min

Step-by-step explanation:

To solve we must follow the following steps:

First, the volume of a cone is given by the equation:

Vc = (1/3) * Pi * (r ^ 2) * h

where r is the radius and h is the height.

they tell us that the height is equal to twice the radius, therefore

h = 2r; r = h / 2

replacing r in the volume of the cone:

Vc = (1/3) * Pi * ((h / 2) ^ 2) * h

solving we have:

Vc = (1/3) * Pi * (1/4) * (h ^ 2) * h

Vc = (1/12) * Pi * h ^ 3

They give us the change in volume with respect to time, that is, dV / dt = 50

It can also be expressed in the following way:

dV / dt = (dV / dh) * (dh / dt)

We know V, so we can derive with respect to h, we are like this:

dV / dh = 3 * (1/12) * Pi * h ^ 2

dV / dh = (1/4) * Pi * h ^ 2

we know that h is equal to 14, therefore:

dV / dh = (1/4) * Pi * 14 ^ 2

dV / dh = (1/4) * 3.14 * 196 = 153.86

Now if we replace

dV / dt = (dV / dh) * (dh / dt)

50 = 153.86 * (dh / dt)

(dh / dt) =  50/158.36

(dh / dt) =  0.3249

This means that the change in height with respect to time is 0.325 feet per minutes.

4 0
2 years ago
Read 2 more answers
What is one fourth of a number decreased by 10,is -50 <br>​
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1/4x - 10 = -50

1/4x = one forth of a number

-10 is decreased by 10

= -50 means is -50

5 0
3 years ago
Read 2 more answers
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andrey2020 [161]
Check the picture below.

notice, the focus point is at 4,5 whilst the directrix line is at y = -3, below the focus point, meaning the parabola is vertical and opening upwards.

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\bf \begin{cases}&#10;h=4\\&#10;k=1\\&#10;p=4&#10;\end{cases}\implies (x-4)^2=4(4)(y-1)\implies (x-4)^2=16(y-1)&#10;\\\\\\&#10;\cfrac{1}{16}(x-4)^2=y-1\implies \cfrac{1}{16}(x-4)^2+1=y

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3 years ago
I've been given this for maths and I have no clue what to do can someone help me out?​
Dmitry [639]
Maths makes no sense sometimes i swear
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2 years ago
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