What is the expected price of a calculator in the year 2000 if it costs $13 in 2015

Answer:

[tex]x = 97[/tex]

Step-by-step explanation:

Given

[tex]t = 20[/tex] --- time (years)

[tex]A =1000[/tex] --- amount

[tex]r = 10\%[/tex] --- rate of interest

Required

The last 10 payments (x)

First, calculate the end of year 1 payment

[tex]y_1(end) = 10\% * 1000 * 150\%[/tex]

[tex]y_1(end) = 150[/tex]

Amount at end of year 1

[tex]A_1=A - y_1(end) - r * A[/tex]

[tex]A_1=1000 - (150 - 10\% * 1000)[/tex]

[tex]A_1 =1000 - (150- 100)[/tex]

[tex]A_1 =950[/tex]

Rewrite as:

[tex]A_1 = 0.95 * 1000^1[/tex]

Next, calculate the end of year 1 payment

[tex]y_2(end) = 10\% * 950 * 150\%[/tex]

[tex]y_2(end) = 142.5[/tex]

Amount at end of year 2

[tex]A_2=A_1 - (y_2(end) - r * A_1)[/tex]

[tex]A_2=950 - (142.5 - 10\%*950)[/tex]

[tex]A_2 = 902.5[/tex]

Rewrite as:

[tex]A_2 = 0.95 * 1000^2[/tex]

We have been able to create a pattern:

[tex]A_1 = 1000 * 0.95^1 = 950[/tex]

[tex]A_2 = 1000 * 0.95^2 = 902.5[/tex]

So, the payment till the end of the 10th year is:

[tex]A_{10} = 1000*0.95^{10}[/tex]

[tex]A_{10} = 598.74[/tex]

To calculate X (the last 10 payments), we make use of the following geometric series:

[tex]Amount = \sum\limits^{9}_{n=0} x * (1 + r)^n[/tex]

[tex]Amount = \sum\limits^{9}_{n=0} x * (1 + 10\%)^n[/tex]

[tex]Amount = \sum\limits^{9}_{n=0} x * (1 + 0.10)^n[/tex]

[tex]Amount = \sum\limits^{9}_{n=0} x * (1.10)^n[/tex]

The amount to be paid is:

[tex]Amount = A_{10}*(1 + r)^{10}[/tex] --- i.e. amount at the end of the 10th year * rate of 10 years

[tex]Amount = 1000 * 0.95^{10} * (1+r)^{10}[/tex]

So, we have:

[tex]Amount = \sum\limits^{9}_{n=0} x * (1.10)^n[/tex]

[tex]\sum\limits^{9}_{n=0} x * (1.10)^n = 1000 * 0.95^{10} * (1+r)^{10}[/tex]

[tex]\sum\limits^{9}_{n=0} x * (1.10)^n = 1000 * 0.95^{10} * (1+10\%)^{10}[/tex]

[tex]\sum\limits^{9}_{n=0} x * (1.10)^n = 1000 * 0.95^{10} * (1+0.10)^{10}[/tex]

[tex]\sum\limits^{9}_{n=0} x * (1.10)^n = 1000 * 0.95^{10} * (1.10)^{10}[/tex]

The geometric sum can be rewritten using the following formula:

[tex]S_n = \sum\limits^{9}_{n=0} x * (1.10)^n[/tex]

[tex]S_n =\frac{a(r^n - 1)}{r -1}[/tex]

In this case:

[tex]a = x[/tex]

[tex]r = 1.10[/tex]

[tex]n =10[/tex]

So, we have:

[tex]\frac{x(r^{10} - 1)}{r -1} = \sum\limits^{9}_{n=0} x * (1.10)^n[/tex]

[tex]\frac{x((1.10)^{10} - 1)}{1.10 -1} = \sum\limits^{9}_{n=0} x * (1.10)^n[/tex]

[tex]\frac{x((1.10)^{10} - 1)}{0.10} = \sum\limits^{9}_{n=0} x * (1.10)^n[/tex]

[tex]x * \frac{1.10^{10} - 1}{0.10} = \sum\limits^{9}_{n=0} x * (1.10)^n[/tex]

So, the equation becomes:

[tex]x * \frac{1.10^{10} - 1}{0.10} = 1000 * 0.95^{10} * (1.10)^{10}[/tex]

Solve for x

[tex]x = \frac{1000 * 0.95^{10} * 1.10^{10} * 0.10}{1.10^{10} - 1}[/tex]

[tex]x = 97.44[/tex]

Approximate

[tex]x = 97[/tex]

Answer:

about 8/25

Step-by-step explanation:

32.3% = 32/100 = 16/50 = 8/25

rounded percentage down.

put over 100

reduce fraction

=======================================================

Explanation:

The triangular face has area of base*height/2 = 8*2/2 = 16/2 = 8 square feet.

Multiply this with the depth of the prism to get 8*12 = 96 cubic feet

----------

For any prism, the volume formula is

V = (area of base)*(depth of prism)

The term "depth" can be replaced with "height" and it's the same idea.

In this problem, we have a triangular prism because the parallel sides are triangles.

Answer:

x=161

Step-by-step explanation:

Answer:

d = 4.5 cm

A = 1/4 (p x d²)

= 1/4 (3.14 x d x d)

= 1/4 (3.14 x 4.5 cm x 4.5 cm)

= 15.9 cm2

The area of the plate nearest square centimeters is 12cm².

A scalene triangle has three different sides and corresponding to that three different interior angles.

According to the given question we have  triangle with sides  4.5cm,6cm and 7.5cm.

We know for a scalene triangle given 3 sides.

area(A) = [tex]\sqrt{s(s-a)(s-b)(s-c)[/tex].

Where S is semi perimeter and a,b,c are the three sides.

= (a+b+c)/2.

= (4.5+6+7.5)/2 cm.

= 18/2 cm.

= 9 cm.

∴ The area of the triangle is

= [tex]\sqrt{9(9-4.5)(9-6)(9-7.5)[/tex]cm².

= [tex]\sqrt{9(4.5)(3)(1.5)}[/tex] cm².

= [tex]\sqrt{182.5}[/tex] cm² this is in between 13 square and 14 square approx 13.5 cm².

Now it has three small circles of radius of 4 mm or 0.4 cm.

We know area of a circle is πr² and area of 3 circles having same radius is 3(πr²) cm².

= 3{π(0.4)²}

= 3{3.14(0.16)} cm².

= 3(0.5024) cm².

= 1.5072 cm².

Now to obtain the area of the scalene triangle with those three holes of 0.4 cm we have subtract the area of the three circles from the triangle which is

= (13.5 - 1.5) cm².

= 12 cm².

learn more about heron's formula here :

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Answer:

Discrete Distribution.

Step-by-step explanation:

For each widget, there are only two possible outcomes. Either they develop paint cracks, or they do not. The probability of a widget developing paint cracks is independent of any other widgets, which means that the binomial probability distribution, which is a discrete distribution, is used to solve this question. Thus the answer is a Discrete Distribution.

9514 1404 393

Answer:

Step-by-step explanation:

You know that cos(α) is a maximum at α=0, 2π, 4π, and all even multiples of π. You know cos(α) is a minimum for α=π, 3π, 5π, and all odd multiples of π.

You can find your value of x at which y will be a maximum by setting the argument of the cosine function equal to zero (and/or 2nπ). If we use α=2nπ, then we have ...

  α = (5π/31)(x -3.2) = 2nπ

  (x -3.2) = (31/5)(2n) = 12.4n

Tidal maxima will occur at ...

 x = 12.4n +3.2 . . . . . for integer values of n

Without bothering to go through the solution for α being odd multiples of π, we can see from this that the period is 12.4 hours. We know the tidal minimum  will be half a period later, or 6.2 hours later than this.

Tidal minima will occur at ...

  x = 12.4n +9.4 . . . . for integers n

__

Of course, cos(α) has extremes of ±1, so your tidal maximum will be ...

  y = 11.412 +174.91 = 186.322

and your tidal minimum will be ...

  y = -11.412 +174.91 = 163.498

Answer:

The answer is 939

Step-by-step explanation:

If you divide 939 by 9 it equals 104 R3.

If you divided 939 by 2 it equals 469 R1

And if you divide 939 by 5 it equals 187 R4

  Hope this helps!

Answer:

19 boys

Step-by-step explanation:

38 kids on the bus

1/2 are girls, that means 1/2 are boys

1/2 * 38 = 19

There are 19 girls and 19 boys

Answer:

The difference between the distances they walked is 600 meters.

Step-by-step explanation:

Let's calculate the distance traveled by Nichol and Sakura with the following equation:

[tex] d = v*t [/tex]

Where:

v: is the speed

t: is the time

The distance traveled by Nichol is:

[tex] d_{n} = 1.2 m/s*15min*\frac{60 s}{1 min} = 1080 m [/tex]

And the distance traveled by Sakura is:

[tex] d_{s} = 1.4 m/s*20 min*\frac{60 s}{1 min} = 1680 m [/tex]

Hence, the difference between the distances they walked is:

[tex] d_{t} = d_{s} - d_{n} = 1680 m - 1080 m = 600 m [/tex]

Sakura traveled 600 meters more than Nichol.

Therefore, the difference between the distances they walked is 600 meters.

I hope it helps you!                    

Answer:

Below in bold.

Step-by-step explanation:

We see from the diagram that:

SY = SK + KY

So, substituting the given values:-

36 - x = 13x - 5 + 2x + 9

-x - 13x - 2x = - 5 + 9 - 36

-16x = -32

x = 32/16 = 2.

So SK = 13(2) - 5 = 21.

KY = 2(2) + 9 = 13.

SY = 36 - 2 = 34.

21 + 13 = 34 so this is a check that our calculation is correct.

Answer:

a function that converges to 0. '' This means that there is some input size past which the function is always between -0.1 and 0.1; there is some input size past which the function is always between -0.01 and 0.01; and so on.

Answer:

68 degrees

Step-by-step explanation:

Since the angle is a right angle, it is 90 degrees, to figure out the measurement of a section if it, simply subtract the known angle 22, from 90 to get an answer of 68.

Answer:

[tex] {x}^{2} + 26x = 11 \\ x = 0.4 \: and \: - 26.4[/tex]

Answer:

-2.5 or - 2 1/2

Step-by-step explanation:

Writing out the expression Mathematically ;

1/3(-15÷1/2)1/4

Using PEMDAS :

Solving the bracket first

(-15 ÷ 1/2) = (-15 * 2/1) = - 30

We have :

1/3(-30)1/4 = - 10 * 1/4 = - 10 / 4 = - 2.5

-2.5 = - 2 1/2

Answer:

Base

Step-by-step explanation:

Every solid shape has to have a base that they sit/stand on. Because the base  is the bottom of the shape and lies on the table. Hence, answering your question.

Hope this helps!

This one was difficult but if your work through it, you will get it.

Keep trying!

Answer:

His practice is 55 minutes long

you can look at it this way

from 5:20pm to 6:pm, is only 40 minutes

then from 6:00pm to 6:15pm is only 15 minutes

40 + 15 = 55

Answer:

The solution of the graph is at (-3,-8).

Step-by-step explanation:

The given equations are :

-4x+3y=-12

and

-2x+3y=-18

These are the system of equations in two variables.

The graphs for the equations are :

The solution of the graph is at (-3,-8).

Answer

19.013.153,42629466 giây

Step-by-step explanati

van toc ánh sán  =299.792.458 m/s

s= v*t

t=s/v

t= 5.699.999.999.999.999/299.792.458= 19.013.153,42629466 giây

Answer:

x = 1.7

Step-by-step explanation:

Answer:

C(min)  =  277.95 $

Container dimensions:

x = 2.822 m

y = 1.411 m

h = 3.52 m

Step-by-step explanation:

Let´s call x  and  y the sides of the rectangular base.

The surface area for  a rectangular container is:

S = Area of the base (A₁) +  2 * area of a lateral side x (A₂) + 2 * area lateral y (A₃)

Area of the base is :

A₁ =  x*y       we assume, according to problem statement that

x  =  2*y      y  = x/2

A₁  =  x²/2

Area lateral on side x

A₂  = x*h           ( h  is the height of the box )

Area lateral on side y

A₃ = y*h        ( h  is the height of the box )

s = x²/2  + 2*x*h + 2*y*h

Cost  =  Cost of the base + cost of area lateral on x + cost of area lateral on y

C = 10*x²/2  + 8* 2*x*h  + 8*2*y*h

C as function of x is:

The volume of the box is:

V(b) = 14 m³  = (x²/2)*h       28 = x²h      h = 28/x²

C(x) = 10*x²/2  + 16*x*28/x² + 16*(x/2)*28/x²

C(x)  =  5*x²  +  448/x  + 224/x

Taking derivatives on both sides of the equation we get:

C´(x)  =  10*x  -  448/x² - 224/x²

C´(x)  =  0             10x  -  448/x² - 224/x² = 0     ( 10*x³ - 448 - 224 )/x² = 0

10*x³ - 448 - 224 = 0       10*x³ = 224

x³  =22.4

x = ∛ 22.4

x = 2.822 m

y = x/2  =  1.411 m

h = 28/x²  =  28 /7.96

h =  3.52 m

To find out if the container of such dimension is the cheapest container we look to the second derivative of C

C´´(x) = 10 + 224*2*x/x⁴

C´´(x)  =  10 + 448/x³    is positive then C has a minimum for x = 2.82

And the cost of the container is:

C = 10*(x²/2) +  16*x*h + 16*y*h

C = 39.82 +  158.75  + 79.38

C =  277.95 $

Answer:

21; the age of the teacher

Step-by-step explanation:

15+x/2=18

Estimate - I estimated in the 20's because it only averaged up a little bit

Started with 23 and kept going until i got to my answer

21

15+21/2

36/2

18

Please mark brainliest :)

Answer:

x = 2 degree and unknown angle = 31 degree

Step-by-step explanation:

149 + 13x + 5 =180 degree (being linear pair)

154 + 13x = 180

13x = 180 - 154

x = 26/13

x = 2 degree

unknown angle = 13x + 5

=13*2 + 5

=26 + 5

=31 degree

The value of the variable x is 2°. Then the value of the unknown angle is 31°.

The inclination is the separation seen between planes or vectors that meet. Degrees are another way to indicate the slope. For a full rotation, the angle is 360 °.

Supplementary angle - Two angles are said to be supplementary angles if their sum is 180 degrees.

Both angles are supplementary angles. Then the equation is given as,

13x + 5° + 149° = 180°

13x + 154° = 180°

13x = 180° - 154°

13x = 26°

x = 26° / 13

x = 2°

The value of the variable x is 2°. Then the value of the unknown angle is given as,

13x + 5° = 13(2°) + 5°

13x + 5° = 26° + 5

13x + 5° = 31°

The value of the variable x is 2°. Then the value of the unknown angle is 31°.

More about the angled link is given below.

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9514 1404 393

Answer:

  h = 7

Step-by-step explanation:

Perhaps you want the solution to ...

  1/(h -5) +2/(h +5) = 16/(h^2 -25)

Parentheses are required around denominators that have math operations.

Multiply by (h^2-25) and solve the linear equation.

  [tex]\displaystyle\frac{1}{h-5}+\frac{2}{h+5}=\frac{16}{h^2-25}\qquad\text{given}\\\\(h+5)+2(h-5)=16\qquad\text{multiply by $h^2-25$}\\\\3h-5=16\qquad\text{simplify}\\\\3h=21\qquad\text{add 5}\\\\\boxed{h=7}\qquad\text{divide by 3}[/tex]

Answer:

x=2

Step-by-step explanation:

the sides are proportional due the angles being equal

since the hypotonuse is 5 on the bigger one and 2.5 on the small one we can infer there is a ×2 difference

so 4÷2=x

x=2