The number of fish in a lake decreased by 15% between last year and this year. This year, there were 51 fish in the lake. What was the population last year? Consider creating a tape diagram, to help you make sense of the situation.​

Answer:

15, 4, 11, 4

Step-by-step explanation:

x=8

so 7+x, 7+8= 15

12-8 = 4

x+3 , 8+3=11

32/8 = 4

Answer:

-7 4/5 or -7.8

Step-by-step explanation:

Product means multiplication

( - 13/8 )( 24/5)

= (-13 · 24)/(8 · 5)    negative · positive = negative

= - 312/40

=  -7  32/ 40 = -7 4/5 or 7.8

Based on the information given, the fraction of horsepower that will be applied to the pump will be 1l28.

From the information given, it can be seen that the motor is rated at 1/8 horsepower and used to drive a pump.

Therefore, the fraction of the horsepower that will be applied to the pump if the motor delivers only 2/7 of its rated horsepower will be:

= 2/7 × 1/8.

= 2/56

= 1/28

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Using the binomial distribution, it is found that there is a 0.5 = 50% probability of selecting a two-child family with one boy and one girl.

For each child, there are only two possible outcomes, either it is a boy, or it is a girl. The probability of a child being a boy or being a girl is independent of any other child, which means that the binomial distribution is used to solve this question.

Binomial probability distribution

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]

The parameters are:

In this problem:

The probability of one of each is P(X = 1), hence:

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

[tex]P(X = 1) = C_{2,1}.(0.5)^{1}.(0.5)^{1} = 0.5[/tex]

0.5 = 50% probability of selecting a two-child family with one boy and one girl.

A similar problem is given at https://brainly.com/question/24863377

Jeremy is incorrect because a negative plus a negative will always be a negative.

Answer:

Hope It's Help

According to her study, we have that:

At the null hypothesis, it is tested if the CBC's students proportion is the same as all community college students, that is, of 32%, hence:

[tex]H_0: p = 0.32[/tex]

At the alternative hypothesis, it is tested if the proportion for CBC's students is greater than 32%, that is:

[tex]H_1: p > 0.32[/tex]

A similar problem is given at https://brainly.com/question/25679468

Answer:

23

Step-by-step explanation:

first off if your to take away 3 from 8 you'd get five and the same goes for the rest

I.e

8-3=5

13-8=5

18+5=23

as 23 -18 would give you you 5

Answer:

B: -9

Step-by-step explanation:

When you add a negative number, you subtract that number.

[tex]18+-27=18-27=-9[/tex]

Answer:

Fertilizer A = 20, Fertilizer B = 56

Step-by-step explanation:

Step 1: Set up the equations

Nitrogen: 8x + 5y ≥ 440

Phosphorous: 2x + 5y ≥ 260

Potassium: 4x + 5y ≥ 360

Step 2: Find the vertices

It is easiest to graph the equations to find the vertices. (see attachment).  You can also solve each system of equations to find the intersected points.

The following satisfy the "greater than or equal to" requirement:

(0, 88) → y-intercept of Nitrogen equation

(20, 56) → intersection of Nitrogen and Potassium equations

(50, 32) → intersection of Phosphorous and Potassium

(130, 0) → x-intercept of Potassium

Step 3: Use vertices in cost function C(x) to find the minimum

C(x) = $30x + $20y

(0, 88): $30(0) + $20(88) = $1760

(20, 56): $30(20) + $20(56) = $1720    ← This is the minimum!

(50, 32): $30(50) + $20(32) = $2140

(130, 0): $30(130) + $20(0) = $3900

The minimum cost occurs when 20 bags of Fertilizer A and 56 bags of Fertilizer B are purchased.  

Answer: B

Step-by-step explanation:

Answer:

700 in^2

Step-by-step explanation:

If A = 225 in- when b = 18 in. and h = 25

225 = 18 * 25 / 2

a = 35 * 40 / 2

a = 700

Answer:

The answer to this is c) 4.

Answer:

Eight pins, each 43/8” long, have to be cut from a piece of drill rod. There is a 3/32” waste for each cut. What is the minimum length of rod you will need? 35” ...

Answer:

480 miles

Step-by-step explanation:

Well, firstly - no idea, as cars can go slower or faster and there is no indication that this particular car would maintain the exact same avg. speed over 12 hours.

There is no way to solve this otherwise though, so we'll assume the car's speed is constant.

280mi / 7h = 40mph

40mph * 12h = 480mi

Answer:

5

Step-by-step explanation:

3+2=5

x=3

Answer:

yes its correct

Step-by-step explanation:

but for the check where did you get the 12? you might want to redo that part but otherwise its right

Answer:

1007/20

Step-by-step explanation:

You helped me so i help you. Here you go my friends sorry i dont have an explanation. Good luck !

Use proportions.  X is what you want.

70      50.35lb

__  =   _____

100          x

Cross multiply to get 70x = 5035

Solve to get about 71.93 lbs of the alloy.

Step-by-step explanation:

check the image for detailed solution

Answer:

2y-3

Step-by-step explanation:

the product of y and 2 is just multiplying

then 3 less means subt. 3

Answer:

  x/12

Step-by-step explanation:

There are 12 inches in a foot.

  feet in x inches = x/12

_____

With units, you have ...

  (x in) × (1 ft)/(12 in) = x/12 ft

Answer:

x=4

Step-by-step explanation:

11x - 2(x + 3) = 30

distribute: 11x-2x-6=30

add like terms: 9x-6=30

add 6: 9x=36

divide by 9: x=4

Answer:

x = 4

Step-by-step explanation:

11x - 2(x +3) = 30

11x -2x - 6 = 30

11x - 2x = 30 + 6

9x = 36

9x/9 = 36/9

x = 4

Answer:

Step-by-step explanation:

y - 4 = 7(x - 1)

y - 4 = 7x - 7

y = 7x - 3

Answer:

Swap 10 from box A and 15 from box B

Step-by-step explanation:

For calculate the ratio between the boxes we find the mean of the box A and the mean of the box B and divide this two results.

For find the mean of a set you use the next formula  [tex]\bar{x} = \frac{\text{sum numbers}}{\text{total numbers}}[/tex]

[tex]\bar{A} = \frac{4+5+9+10+12}{5} = \frac{40}{5}= 8\\\bar{B} = \frac{6+7+13+15+19}{5} = \frac{60}{5}= 12[/tex]

Then the ratio is equal to [tex]\frac{\bar{A}}{\bar{B}} = \frac{8}{12} = \frac{2}{3}[/tex]

Know the ask us for a ratio of 9:11 then we know two things about the boxes.

If you swap the numbers between them the total of numbers in the mean not change is always 5 and the sum of all the elements in both boxes is always 100. With this we can state the next equation:

The new mean of [tex]\bar{A}[/tex] is 9 then:

[tex]\frac{\text{sum of elements in box A}}{5} = 9[/tex]

[tex]\text{sum of elements in box A} = 45[/tex]

The new mean of [tex]\bar{B}[/tex] is 11 then:

[tex]\frac{\text{sum of elements in box B}}{5} = 11[/tex]

[tex]\text{sum of elements in box B} = 55[/tex]

Now we know what is the sum of the elements in both boxes, but how we find the elements for swap? Well with the next relation.

When you take out a element from the box A this elements is substracted to the total sum of the elements in the box A and get a new sum of total of elements named [tex]c[/tex] (where [tex]a[/tex] is the element taken):

[tex]40 - a = c[/tex]

And when you sum an element to the box A the current sum of total elements in the box change to (where [tex]b[/tex] is the added element):

[tex]b + c = 45[/tex]

So replace [tex]c[/tex] for the first relation and get:

[tex]b + 40 - a = 45\\b - a = 5[/tex]

From the last equation you can deduct that [tex]b[/tex] is greater than [tex]a[/tex] and the different between both values is 5. So the last step is find a number in the box B that substracted to a number from the box A give us 5. These both numbers are 15 and 10 because 15 - 10 = 5.

Answer:

a

Step-by-step explanation:

just took the test

The answer would be 8:16

Answer:

10 twenty cent pieces and 6 fifty cent pieces for 16 coins and 5 euros.

Step-by-step explanation:

Answer:

Step-by-step explanation:

x + y = 18

y = 18 - x

xy = 72

x(18 - x) = 72

-x² + 18x = 72

0 = 72 - 18x + x²

x = (18 ± √(18² - 4(1)(72))) / (2(1))

x = (18 ± 6)/2

x = 12

x = 6

Answer:

[tex]\huge\boxed{-0.001a^{n+1}}[/tex]

Step-by-step explanation:

[tex]-0.001a^{3n+3}=-0.001a^{3(n+1)}=(-0.001a^{n+1})^3\\\\\text{Used}\\\\a(b+c)=ab+ac\qquad\text{distributive property}\\\\(a^n)^m=a^{n\cdot m}[/tex]

Answer: the answer is 3:20pm!

Step-by-step explanation:

i got the question correct just now!

Answer:

3;20

Step-by-step explanation: