Suppose a lab need to need to make 400 liters of 39% acid solution, but the only solutions available to the lab are 20% acid and 50% acid. What system of equation can be used to find the number of liters of each solution the should be mixed to make the 39% solution? Let c represent the number of liters of 20% acid solution and let d represent the number of liters of 50% acid solution.

Answers

Answer 1

Answer:

c + d = 400

0.2c + 0.5d = 156

Step-by-step explanation:

Let

c = number of liters of 20% acid solution

d = number of liters of 50% acid solution.

c + d = 400 (1)

0.2c + 0.5d = 400(0.39)

0.2c + 0.5d = 156 (2)

From (1)

c = 400 - d

Substitute c = 400 - d into (2)

0.2c + 0.5d = 156 (2)

0.2(400 - d) + 0.5d = 156

80 - 0.2d + 0.5d = 156

- 0.2d + 0.5d = 156 - 80

0.3d = 76

d = 76/0.3

d = 253.33 liters

Substitute d = 253.33 into (1)

c + d = 400

c + 253.33 = 400

c = 400 - 253.33

c = 146.67 liters


Related Questions

Joel has a prepaid phone card that charges $0.50 to connect and $0.50 per minute. He also can use a cell phone that charges $2.50 to connect and $0.25 per minute. In how many minutes will calls made using the phone card and the cell phone cost the same?

Answers

Answer:12 minutes

Hope this is right sorry if not <3

To complete a planter box, mr. Michaels will purchase cedar boards that are 2 inches wide and 8 inches long. He will need to cut down the length of the boards into pieces that are 1 1/3 inches long. How many pieces can mr. Michael cit from each 8 inch board so he can determine how many he will need to purchase?

Answers

Answer:

6 pieces

Step-by-step explanation:

Since Mr. Michaels need to cut down the 8 inch long boards into pieces that are 1¹/₃ inches long, the number of pieces he can cut out from the 8 inch long board that are 1¹/₃ inches long is 8 ÷ 1¹/₃ = 8 ÷ 4/3

= 8 × 3/4

= 2 × 3

= 6

So, Mr. Michaels can cut 6 pieces that are 1¹/₃ inches long from the 2 inches wide and 8 inches long board.

You have two regular polygons
A & B
. The ratio of the interior angles of
A & B
is

21: 22
. The ratio of the exterior angles is
3:2
. How many sides does each polygon have?

Answers

Answer:

First polygon has 16 sides

Second polygon has 24 sides

Step-by-step explanation:

Let the number of sides for first polygon be a and that for the second polygon be b

formula for sum of interior angle is;

180n-360

So for individual interior angle we have;

(180n-360)/n

So for polygon A

(180a-360)/a

For polygon B

(180b-360)/b

Let’s divide both to equate to the ratio

(180a-360/a)/(180b-360)/b) = 21/22

Factor out 180

(a-2)/a * b/b-2 = 21/22

b(a-2)/a(b-2) = 21/22

22b(a-2) = 21a(b-2) •••••• (i)

For the second part

Sum of exterior angle of any polygon is 360

Individual exterior angle is 360/n

for the first polygon;

360/a ;

For the second 360/b

Thus;

b/a = 3/2

2b = 3a ••••••••(ii)

b = 3a/2

11(2b)(a-2) = 21a(b-2)

11(3a)(a-2) = 21a( 3a/2-2)

33a(a-2) = 21a(3a-4)/2

22a(a-2) = 7a(3a-4)

22a^2 - 44a= 21a^2-28a

22a^2-21a^2+28a - 44a = 0

a^2 + 28a - 44a = 0

a^2 -16a = 0

a(a-16) = 0

a = 0 (which cannot be)

or a-16 = 0

a = 16

Recall;

b = 3a/2

b = 3(16)/2

b = 24

Myra gets paid at home for doing extra chores. Last week, she did 5 loads of laundry and 8 loads of dishes, and her parents paid her $18. The week before, she finished 4 loads of laundry and 6 loads of dishes, earning a total of $14. How much does Myra earn for completing each type of chore?

Answers

Answer: Laundry = $2

Dishes= $1

Step-by-step explanation:

Let the amount paid for doing laundry be x

Let the amount paid for doing dishes be y.

Based on the information in the question, this can be formed in an equation as:

5x + 8y = 18 ..... i

4x + 6y = 14 ...... ii

Multiply equation i by 4

Multiply equation ii by 5

20x + 32y = 72 ...... iii

20x + 30y = 70 ...... iv

Subtract iv from iii

2y = 2

y = 2/2 = 1

Dishes cost $1

Since 5x + 8y = 18

5x + 8(1) = 18

5x = 18 - 8

5x = 10

x = 2

Laundry cost $2

Aiden cuts a ball of string into 14 equal pieces. The length of each piece of string is 2 1/4 yards. What is the original length of the ball of string?

Answers

Answer:

31 1/2 yards

Step-by-step explanation:

In order to calculate the original length of the ball of string we simply need to multiply the length of each piece of string by the total number of strings that were produced from the original ball of string. First, we can turn the 2 1/4 into a single decimal number. Since 1/4 is equal to 0.25 we just add this to 2 to get 2.25, now we can go ahead and multiply this by the 14 total pieces.

2.25 * 14 = 31.5 or 31 1/2 yards

what is 5000000000000000times 409458374.9394ir

Answers

Answer:

2,047,291,874,697,000,000,000,000

Step-by-step explanation:

that is the answer to the multiplication statement xD

BRAIN TWISTER/6TH GRADE MATH

Create (1) mathematical problem or mathematical sentence where the answer is "46". For the variables, use t = 3 and h= 5 or t and h for equations.

Answers

7h + 2t = 46

When t = 3 and h = 5

find the values of z and y plssss

Answers

Answer:

z is 23 and i dont see a y

Step-by-step explanation:

if the mean of 6 7 13 and 10 is 8 find rangeif the mean of 67 13 and 10 is 8 find range ​

Answers

Answer:

The range is: 7

Step-by-step explanation:

Given the data set

6, 7, 13, 10

Sorting in ascending order

6, 7, 10, 13

We know that the range is the difference between the highest and lowest values in a set of numbers.

Here:

Highest Value = 13Lowest Value = 6

Thus,

Range = Highest Value - Lowest Value

           = 13 - 6

           = 7

Therefore, the range is: 7

Solving a Real-World Problem
Mr. Martin is giving a math test next period. The test, which is worth 100 points, has 29 problems. Each problem is
worth either 5 points or 2 points. Write a system of equations that can be used to find how many problems of each
point value are on the test.
Let x be the number of questions worth 5 points and let y be the number of questions worth 2 points.
x + y = 29, 5x + 2y = 100
x + y = 100, 5x + 2y = 29
5x + y = 29, 2y + x = 100
2x + y = 100, 5y + x = 29

Answers

Answer:

x + y = 29

5x + 2y = 100

Step-by-step explanation:

Here, we want to set up equations

There are 29 problems, so adding up the number of individual problem types will give 29

x + y = 29 ••••••(i)

Let us work with points now;

x is worth 5 points, y is worth 2 points

Thus, mathematically;

5x + 2y = 100 ••••••••••(ii)

Answer: A. x + y = 29, 5x + 2y = 100 and the other one is B. 14 problems worth 5 points and 15 problems worth 2 points

need to know soon! please help​

Answers

Answer:

59

Step-by-step explanation:

62+59= 121

180-121= 59

Answer:

m<1 = 121

Step-by-step explanation:

59 + 62 = 121

180 - 121 = 59

180 - 59 = 121

The volume of a cylinder is 176 cm and its height is 11 cm,
What is the length of the cylinder's radius?

Answers

Answer:

4cm

Step-by-step explanation:

The volume of the cylinder is the product of the area of the base and the height. In mathematical equation, this can be written as,

                                     V = πr²h

where V is volume, r is the radius, and h is the height.

Substituting the known values from the given,

                                 176π cm³ = πr²(11 cm)

The side length of aDavid is a statistician. He has a sample size of 40 (which he cannot change). What element of his hypothesis test can he adjust to minimize the probability that he incorrectly rejects the null hypothesis?
the mean of the population
the mean of the sample
the standard deviation of the population
the significance level of the testn equilateral triangle is 6 cm. What is the height of the triangle?

Answers

Answer: D) the significance level of the test

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

Explanation:

The significance level of the test, also known as "alpha", is the probability of making a type 1 error. A type 1 error is where you reject the null hypothesis but it was true all along.

The null hypothesis is where we test a certain probability distribution (eg: normal distribution). Specifically we gather a sample of values and compute the test statistic. If the probability of getting that test statistic or more extreme is smaller than alpha, then we reject the null. This probability value is known as the p-value.

If you lower the alpha value, then that will make it more likely you do not reject the null. Consider an example where alpha = 0.10 to start with. If you get a p-value of 0.02, then you would reject the null. The same would apply for alpha = 0.05; however, with alpha = 0.01, the p-value is no longer smaller than alpha. At this point we do not reject the null. Your textbook may use the phrasing "fail to reject the null".

Going in the opposite direction, increasing the alpha value will make it more likely to reject the null. Each time you adjust the alpha value, keep the p-value to some fixed number (between 0 and 1).

The height of the equilateral triangle is 3√3 cm.

What is hypothesis testing?

Hypothesis testing is a statistical method that is used to make decisions about a population based on a sample of data.

It involves testing a null hypothesis (H0) against an alternative hypothesis (Ha) using statistical techniques.

We have,

To minimize the probability of incorrectly rejecting the null hypothesis in a hypothesis test with a fixed sample size of 40, the statistician can adjust the significance level of the test.

The significance level, denoted by α, is the probability of rejecting the null hypothesis when it is actually true.

By choosing a smaller significance level, the statistician can decrease the probability of making a Type I error (rejecting the null hypothesis when it is actually true).

However, decreasing the significance level also increases the probability of making a Type II error (failing to reject the null hypothesis when it is actually false).

Therefore,

The choice of significance level involves a trade-off between the two types of errors and should be based on the specific context of the problem and the consequences of each type of error.

Now,

The height of an equilateral triangle can be found using the formula:

height = (side length / 2) x √3

The side length = 6 cm

So,

height = (6 / 2) x √3

           = 3√3 cm

Therefore,

The height of the equilateral triangle is 3√3 cm.

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Original price of a computer game: $24.50
Discount: 20%
What is the selling price

Answers

Answer:

You will pay $19.6 for a item with original price of $24.50 when discounted 20%. In this example, if you buy an item at $24.50 with 20% discount, you will pay 24.50 - 4.9 = 19.6 dollars.

Step-by-step explanation:

For the equation 2x + 7 =30, x = 3
O True
O False

Answers

The answer is false
Have a good day <3

Answer:  False

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

Explanation:

To see if the x value is a solution or not, we plug it into the equation given

2x+7 = 30 .... original equation

2*3 + 7 = 30 .... replace every x with 3, since we claim that x = 3

6 + 7 = 30 .... multiply 2 and 3 to get 6

13 = 30 ...... add 6 and 7 to get 13

We get two different numbers on either side, so the last equation is not true. We get a contradiction or false statement. So the original equation is false when x = 3. Therefore, x = 3 is not the solution.

That's why the overall claim is false.

Please Answer! This is urgent!

Answers

Step-by-step explanation:

If the perimeters could be equal,

then 4(x + 3) = 2(x + 4 + x + 1).

=> 4x + 12 = 2(2x + 5)

=> 4x + 12 = 4x + 10

However 12 =/= 10 for all real values of x. Hence their perimeters can never be equal.

Find each function value f(-7) if f(x) = 3x + 6

Answers

Answer:

-15

Step-by-step explanation:

3*-7=-21+6=-15

Answer:

Step-by-step explanation:

first multiply -7 and 3 since -7 is the element of the function (x)

then you should get (-21)

now add 6 and you answer should be (-15)

The ration of child to teen to adult tickets sold at a water park on Saturday was 4:1:2. A total of 294 tickets were sold. How many child tickets were sold?

Answers

Answer:  168 child tickets were sold.

Step-by-step explanation:

Given: The ratio of child to teen to adult tickets sold at a water park on Saturday was 4:1:2.

Let the number of child tickets = 4x , teen tickets = x , adult tickets = 2x

Total tickets = x+4x+2x = 7x =294

[tex]\Rightarrow\ x=\dfrac{294}{7}\\\\\Rightarrow\ x=42[/tex]

Number of child tickets = 4(42) = 168

Hence, 168 child tickets were sold.

Nick and eddie are both thinking of a number. Eddies number is 3/7 of nicks number. There is a difference of 52 between their two numbers. What are the two numbers

Answers

Answer:

nick's number = 91

eddie's number = 39

Step-by-step explanation:

n = nick's number

[tex]\frac{3}{7}[/tex]n = eddie's number

[tex]\frac{7}{7}[/tex]n - [tex]\frac{3}{7}[/tex]n = 52

[tex]\frac{4}{7}[/tex]n = 52

cross-multiply:  4n = 52(7)

                         4n = 364

                          n = 364/4 = 91

eddie's number:  [tex]\frac{3}{7}[/tex] · 91 =  273/7 = 39

Nick's number is 91

Eddie's number is 39

What is expression?

An expression is a combination of terms that are combined by using mathematical operations such as subtraction, addition, multiplication, and division. The terms involved in an expression in math are:

Constant: A constant is a fixed numerical value.

Variable: A variable is a symbol that doesn't have a fixed value.

Term: A term can be a single constant, a single variable, or a combination of a variable and a constant combined with multiplication or division.

Coefficient: A coefficient is a number that is multiplied by a variable in an expression.

Given,

Eddie's number is 3/7 of Nick's number

Let Nick's number be x

Then Eddie's number = 3x/7

Difference of the numbers is 52

x - 3x/7 = 52

(7x - 3x)/7 = 52

4x/7 = 52

4x = 52×7

x = 364/4

x = 91

Another number = 3x/7

                            = 3(91)/7

                            = 3 × 13

                            = 39

Hence, 91 is Nick's number and 39 is Eddie's number.

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A triangle has a base of two to the third power units and a height of chicken fourth power units what is the area of the triangle

Answers

i think you had an auto correct problem

Please help!
And explain the answers too!

Answers

1) He worked 4 hours leaving 6 more hours for him.
rate for A alone 6 baker
rate for A & B together 4
1/a+1/b=1/x
1/6+1/b=1/4
1/b=1/4-1/6
1/b=6/24-4/24
1/b=2/24
1/b=1/12
b=12
rate for wife alone 12 hours for the remaining 6 hours
check
1/6+1/12=1/4
12/72+6/72=1/4
18/72=1/4
ok
codewa
But we want to know how long it would have taken her for the whole job not just part of it
he works twice as fast as she does so the job that takes him 10 hours alone would take her 20 hours alone.

2) jessica and cynthia work in a pet shop.
it takes jessica 6 hours to groom all the pets but cynthia needs 8 hours to groom them.
if jessica starts to groom 1 hour before cynthia joins, how long will it take them to finish?
:
let t = time it takes them to finish (C's working time)
then
t+1 = J's working time
let 1 = completed job (all pets groomed)
:
A shared work equation, each does a fraction of the job, the two fractions add up to 1
%28%28t%2B1%29%29%2F6 + t%2F8 = 1
Multiply by the least common multiple of 6 and 8, 24. cancel the denominators
4(t+1) + 3t = 24
4t + 4 + 3t = 24
4t + 3t = 24 - 4
7t = 20
t = 20/7
t = 26%2F7 hrs, which is: 2 + 6%2F7*60 = 2 hrs 51.43 min to finish the job

3) math club takes 40 minutes
science takes 50 minutes.
rate * time = quantity
quantity = 1 set up of the tables.
rate for math club is 1/40 of all the tables in 1 minute.
rate for science club is 1/50 of all the tables in 1 minute.
math club works for 10 minutes.
rate * time = quantity
1/40 * 10 = 10/40 = 1/4 of the tables are already set up by the math club.
there are 3/4 of the tables that still need to be set up.
rate * time = quantity
the rates of the math club and the science club are additive.
(1/40 + 1/50) * time = 3/4 of the tables that still need to be set up.
common denominator is 200.
(5/200 + 4/200) * time = 3/4.
9/200 * time = 3/4
time = 3/4 * 200/9 = 600 / 36 = 16 and 2/3 minutes.
total time required is 10 + 16 + 2/3 minutes = 26 + 2/3 minutes.
how to check.
10 minutes is used to do 1/4 of the tables.
16 + 2/3 minutes is used to do the remaining 3/4 of the tables.
combined rate of math and science club is 9/200 of the tables in 1 minute.
math club rate of 1/40 * 10 = 10/40 = 1/4 of the tables.
combine rate of 9/200 * (16 + 2/3) = 9/200 * 50/3 = 450/600 = 9/12 = 3/4 of the tables.
1/4 + 3/4 = 1 = all of the tables.

can I get help with this

Answers

Answer:

$3,600

Step-by-step explanation:

To find the total amount we can state that $270 divided by 0.075 can find us the total amount of office receipts.

Doing so, we get: $270 over 0.075 = $3,600

On a long hike, Greg forgets to fill his canteen. Fortunately, Harold has 40 ounces of water and jake has 60 ounces. The three hikers share water so that each gets an equal amount. At the end of the hike, Greg gives Harold and Jake $5 to split for the water they gave him. How much should Harold and Jake get?

Answers

Answer:

Jake should get $3 because he would have given more water since he had the most out of all of them. Harold should get $2 because he gave less water

Step-by-step explanation:

The amount that Harold and Jake will get is $2 and $3, respectively.

What is a Ratio?

A ratio shows us the number of times a number contains another number.

Harold has 40 ounces of water, which is needed to be shared among the three, therefore, the amount of water that each of the three will get is,

Amount of water = Total water / Number of persons

                             = 40 ounces of water / 3 person

                             = (40/3) ounces per person

Thus, Greg will get (40/3) ounces of water from Harold.

Similarly, Jake has 60 ounces of water, which is needed to be shared among the three, therefore, the amount of water that each of the three will get is,

Amount of water = Total water / Number of persons

                             = 60 ounces of water / 3 person

                             = (60/3) ounces per person

Thus, Greg will get (60/3) ounces of water from Harold.

Further, Harold and Jake will get the money in the ratio of the amount of water they shared, therefore, we can write,

(40/3)x + (60/3)x = $5

(40x + 60x)/3 = 5

100x = 5 × 3

x = 15/100

Furthermore, the money each of two will get is,

Amount that Harold will get,

(40/3)x

= (40/3) × (15/100)

= $2

Amount that Jake will get,

(60/3)x

= (60/3) × (15/100)

= $3

Hence, the amount that Harold and Jake will get is $2 and $3, respectively.

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Regina carns $7.25 per hour for babysitting her little sister how many hours must Regina work to earn $464

Answers

Answer:

64

Step-by-step explanation:

464 / 7.25 = 64

Judy is selling small candles at the fair for $4 each and large candles for $6 each. She collected $144 selling a
total of 28 candles. How many of each candle did she sell? Use x for the small candles and y for the large
candles.

Answers

12 small candles, 16 large candles.

HOW TO SOLVE

Let x = the number of small candles sold
Let y = the number of large candles sold

You are given two pieces of information:

(1) Number of candles sold: x + y = 28
(2) Revenue based on cost per candles sold: 4x + 6y = 144

Two equations, two unknowns - Solving by substitution (x = 28 - y)

4 * (28-y) + 6y = 144
112 - 4y + 6y = 144
112 + 2y = 144
2y = 32
y = 16

If y = 16, back substitute to find x = 12

Double check using revenue generated:

4x + 6y = 144
4(12) + 6(16) =? 144
48 + 96 = 144

Select the correct answer. What is the solution of
[tex] \frac{5}{2}x - 7 = \frac{3}{4}x + 14[/tex]
A. x = -6
B. x = 6
C. x = 8
D. x = 12​

Answers

Answer:

Option D

Step-by-step explanation:

[tex] \frac{5x}{2} - 7 = \frac{3x}{4} + 14[/tex]

[tex] = > \frac{5x}{2} - \frac{3x}{4} = 14 + 7[/tex]

[tex] = > \frac{7x}{4} = 21[/tex]

[tex] = > x = \frac{21 \times 4}{7} = 12[/tex]

ILL MAKE BRAINLEST YOUR GONNA HAVE TO ZOOM IN BUT AM I RIGHT

Answers

Yes you are right good luck
I zoomed and I still can’t see sorry

mr martin has 36 calculators in a box. The ratio of the ordinary calculators to the scientific 5:1. How many of each calculator does he have

Answers

Answer:

180 calculators.

Step-by-step explanation:

She has 180 calculators because if you were to un - simplify 5:1 you would get 180:5 and you would use the first number. So, you have 180 calculators.

Sorry if this is wrong I tried my best.

On the first day, you pay $5 for 2 boxes of popcorn.
The next day you pay $7.50 for 3 boxes. Are the ratios
equivalant.

Answers

Answer:

10 5

Step-by-step explanation:

Answer:  Yes

Step-by-step explanation:

First find the unit rate by find the cost per box.

To find the cost per post you will divide the cost by the number of boxes.

5/ 2 = 2.5

7.50/ 3  = 2.5  

2.5  is indeed equal to 2.5 so they are equivalent.

whats three hundred x three hundred 300x300

Answers

Answer:

90000

Step-by-step explanation:

this baby has big brain

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