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3 years ago

What number is 80% of 90?

Mathematics

1 answer:

Lerok [7]3 years ago

4 0

The answer is 72

b/c 80% is equal to .80

so you do 90x.80

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A chemist mixed 5 mL of Solution A with every 3 mL of Solution B to make a new solution

Nana76 [90]

Answer:

5:3

Step-by-step explanation:

Given that the chemist mixed 5 mL of Solution A with every 3 mL of Solution B to make a new solution with a new concentration.

So, the amount of Solution A in the mixture, a = 5 mL

The amount of Solution B in the mixture, b = 3 mL

Therefore, the ratio of Solution A to Solution B in the new solution with the same concentration is a:b=5:3.

Hence, the required ratio for the same concentration is 5:3.

Please note that none of the given options matched.

3 0

2 years ago

You are designing a rectangular poster to contain 7575 in2 of printing with a 33-in margin at the top and bottom and a 11-in m

erma4kov [3.2K]

Answer:

The dimensions of the rectangular poster is 15 in by 5 in.

Step-by-step explanation:

Given that, the area of the rectangular poster is 75 in².

Let the length of the rectangular poster be x and the width of the rectangular poster be y.

The area of the poster = xy in².

$\therefore xy=75$

$\Rightarrow y=\frac{75}{x}$ ....(1)

1 in margin at each sides and 3 in margin at top and bottom.

Then the length of printing space is= (x-2.3) in

=(x-6) in

The width of printing space is = (y-2.1) in

=(y-2) in

The area of the printing space is A =(x-6)(y-2) in²

∴ A =(x-6)(y-2)

Putting the value of y

$\Rightarrow A =(x-6)(\frac{75}{x}-2)$

$\Rightarrow A = 87-\frac{450}{x}-2x$

Differentiating with respect to x

$A '= \frac{450}{x^2}-2$

Again differentiating with respect to x

$A''=-\frac{900}{x^3}$

To find the minimum area of printing space, we set A' = 0

$\therefore \frac{450}{x^2}-2=0$

$\Rightarrow 450 =2x^2$

$\Rightarrow x^2=225$

$\Rightarrow x=\pm 15$

Now putting x=±15 in A''

$A''|_{x=15}=-\frac{900}{15^3}$

$A''|_{x=-15}=-\frac{900}{(-15)^3}=\frac{900}{(15)^3}>0$

Since at x=15 , A"<0 Therefore at x=15 , the area will be minimize.

From (1) we get

$y=\frac{75}{x}$

Putting the value of x

$y=\frac{75}{15}$

=5 in

The dimensions of the rectangular poster is 15 in by 5 in.

4 0

3 years ago

Jamel is asked to create triangles using three of four given sticks. The sticks measure 3 in., 6 in., 7 in., and 8 in. He create

Dmitriy789 [7]

Let c = hypotenuse and a = leg 1 and b = leg 2. If c² > a² + b², then it is obtuse. If it is less, then it is acute. I hope it helps.

4 0

2 years ago

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What is the distance between Point A and Point B?

Lelechka [254]

Answer:

"2 units" is the answer.

7 0

3 years ago

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How can you make 64, multiplying just two numbers?

Darina [25.2K]

These are all the answers to this question!

1 x 64 = 64

2 x 32 = 64

4 x 16 = 64

8 x 8 = 64

16 x 4 = 64

32 x 2 = 64

64 x 1 = 64

7 0

3 years ago

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