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3 years ago

Rani takes a 40-question test. She answers 5% of the questions incorrectly

Mathematics

1 answer:

Feliz [49]3 years ago

5 0

Answer:

2 Questions.

Step-by-step explanation:

To calculate a how much a percentage is of a number, you multiply the number by the percent.

So, we have the equation:

40 x 0.05 = 2

So, Rani got 2 questions incorrect.

Hope this helps!

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The diameter of an insect cell is 1.7 × 10–11 meter. Ariel wants to find the length of the radius of the cell. If she performs t

Juli2301 [7.4K]

Answer:

8.5E-12

Step-by-step explanation:

According to the Question,

Given That, The diameter of an insect cell is 1.7 × 10^-11 meters.

Ariel wants to find the length of the radius of the cell. Radius Is Half of the Diameter.

Thus, R = D/2 ⇒ (1.7*10^-11)/2 = 0.85× 10^-11
If she performs the calculations on her calculator is 8.5E-12.

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2 years ago

My Notes A street light is mounted at the top of a 15-ft-tall pole. A man 6 ft tall walks away from the pole with a speed of 4 f

Sergio [31]

Answer:

6.667 ft/s

Step-by-step explanation:

Given

Height of street light = 15ft

Height of man = 6ft

Speed away from pole = 4ft/s

Let x represents the distance between the man and the pole, and Let y represents the distance between the tip of the man's shadow to the pole.

This forms a similar triangle (see attachment below).

From similar triangles, we have

(y - x)/6 = y/15 ----- Solve equation

15(y - x) = 6 * y

15y - 15x = 6y ---- Collect Like Terms

15y - 6y = 15x

9y = 15x --- divide through by 9

y = 15x/9

y = 5x/3 ---- differentiate with respect to time, t

dy/dt = 5/3 dx/dt

dx/dt represents rate of change of distance per time = 4ft/s

while dy/dt represents rate of movement of his shadow tips

dy/dt = 5/3 * 4

dy/dt = 20/3 = 6.667 ft/s

4 0

3 years ago

Read 2 more answers

Randall’s family drove to the beach for vacation. Assume they drove the same speed throughout the trip. The first day, they drov

Vlad1618 [11]

<span>Randall’s family drove to the beach for vacation. Assume they drove the same speed throughout the trip. The first day, they drove 130miles in 22 hours. The second day, they drove 325 miles in 55 hours. The third day, they arrived at the beach by driving 390 miles in 66 hours.</span>

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3 years ago

Find the x-intercept of the parabola of with vertex (1,20) and the y-intercept (0,16). write your answer in this form: (x1,y1),(

svetoff [14.1K]

I assume that the parabola in this particular problem is one whose axis of symmetry is parallel to the y axis. The formula we're going to use in this case is (x-h)2=4p(y-k). We know variables h and k from the vertex (1,20) but p is not given. However, we can solve for p by substituting values x and y in the formula with the y-intercept:

(0-1)^2=4p(16-20)

Solving for p, p=-1/16.

Going back to the formula, we can finally solve for the x-intercepts. Simply fill in variables p, h and k then set y to zero:

(x-1)^2=4(-1/16)(0-20)
(x-1)^2=5
x-1=(+-)sqrt(5)
x=(+-)sqrt(5)+1

Here, we have two values of x

x=sqrt(5)+1 and
x=-sqrt(5)+1

thus, the answers are: (sqrt(5)+1,0) and (-sqrt(5)+1,0).

5 0

3 years ago

Write an exponential function for the graph that passes through the points (0,4) and (2, 36). Use the formula y=ab^x

fomenos

Answer:

Using the equation y = abx , substitute both of your given points into that equation.

2 = ab2 and 4 = ab3 Solve each equation for a.

2⁄b2 and 4⁄b3 = a Therefore, 2⁄b2 = 4⁄b3

Cross multiply: 2b3 = 4b2 Divide both sides by b2

2b = 4 a = 2/4 = 1/2

b = 2

y = 1 (2)x

Step-by-step explanation:

3 0

3 years ago