Mark got 18 out of 25 questions correct on his science test. What percent of the questions did he get incorrect

This question s incomplete, the complete question is;

The Watson family and the Thompson family each used their sprinklers last summer. The Watson family's sprinkler was used for 15 hours. The Thompson family's sprinkler was used for 30 hours.

There was a combined total output of 1050 of water. What was the water output rate for each sprinkler if the sum of the two rates was 55L per hour  

Answer:

The Watson family sprinkler is 40 L/hr while Thompson family sprinkler is 15 L/hr

Step-by-step explanation:

Given the data in the question;

let water p rate for Watson family and the Thompson family sprinklers be represented by x and y respectively

so

x + y = 55  ----------------equ1

x = 55 - y ------------------qu2

also

15x + 30y = 1050

x + 2y = 70 --------------equ3

input equ2 into equ3

(55 - y) + 2y = 70

- y + 2y = 70 - 55

y = 15

input value of y into equ1

x + 15 = 55

x = 55 - 15

x = 40

Therefore, The Watson family sprinkler is 40 L/hr while Thompson family sprinkler is 15 L/hr

Answer:

x=-0.26

Step-by-step explanation:

Answer:

30x - 28

Step-by-step explanation:

distribute

5(2x) - 5(4) -4(2) - 4(-5x)

10x - 20 - 8 + 20x

30x - 28

Answer:

a) 0.0031 = 0.31% probability of marking exactly 3 incorrect answers.

b) 0.0035 = 0.35% probability of passing.

Step-by-step explanation:

For each question, there are only two possible outcomes. Either the student chooses the correct answer, or he does not. Questions are independent of each other. So we use the binomial probability distribution to solve this question.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

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

In which [tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by the following formula.

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

And p is the probability of X happening.

10 multiple choice questions

This means that [tex]n = 10[/tex]

4 answers that are equally likely to be the correct one. The quiz taker selects the answers randomly.

This means that [tex]p = \frac{1}{4} = 0.25[/tex]

a) Probability of marking exactly 3 incorrect answers.

3 incorrectly = 7 correctly, so this is P(X = 7).

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

[tex]P(X = 7) = C_{10,7}.(0.25)^{7}.(0.75)^{3} = 0.0031[/tex]

0.0031 = 0.31% probability of marking exactly 3 incorrect answers.

b) Probability of passing

At least 7 correct, so

[tex]P(X \geq 7) = P(X = 7) + P(X = 8) + P(X = 9) + P(X = 10)[/tex]

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

[tex]P(X = 7) = C_{10,7}.(0.25)^{7}.(0.75)^{3} = 0.0031[/tex]

[tex]P(X = 8) = C_{10,8}.(0.25)^{8}.(0.75)^{2} = 0.0004[/tex]

[tex]P(X = 9) = C_{10,9}.(0.25)^{9}.(0.75)^{1} \approx 0[/tex]

[tex]P(X = 10) = C_{10,10}.(0.25)^{10}.(0.75)^{0} \approx 0[/tex]

[tex]P(X \geq 7) = P(X = 7) + P(X = 8) + P(X = 9) + P(X = 10) = 0.0031 + 0.0004 + 0 + 0 = 0.0035[/tex]

0.0035 = 0.35% probability of passing.

Answer:

3:2

Step-by-step explanation:

to write a ratio, we can do ?:? in order. for example, 5 big shops to 10 small shops would be 5:10 (we are going to simplify it later) You always have to put the ratio numbers in order like they are in the question. In this case, small bones : big bones. We get 9:6. We can then divide both sides by a common factor, in this case 3. The end result is 3:2. Hope this helps!

Answer:

36+41+59+36+27=199

Step-by-step explanation:

Answer:

203

Step-by-step explanation:

first grade 36

Second grade 36+7=43

third grade 36+25=61

forth grade 36

fifth grade 36-9=27

36+43+61+36+27=203

Answer:

arithmetic

Step-by-step explanation:

Answer:

50

Step-by-step explanation:

you need to put  first the 32 on top of 100 since it always goes over 100 then you put 16 over a blank and you divide 32 by 16 which equals 2 so since you divided at the top you need to divide at the bottom so you divide 100 by 2 and you get 50 so 50 is your answer

Answer:

Step-by-step explanation:

Let the transmitter be located at (0,0)

The equation for its effective coverage area will be a circle centered at  (0,0)  with a radius of 49.

So....the equation is  

[tex]x^2 + y^2 = 49^2[/tex]

[tex]x^2 + y^2 = 2401[/tex]

Let the point 67 miles north of the transmitter be (0, 67)

Let the point 63  miles east of the transmitter be (63, 0)

The line connecting these (the line of travel)  will have a slope of

[67 - 0] / [ 0 - 63]  =  -67/63

The equation of this line will be: y  = (-67/63)x  + 67

The signal will be received between the points:

(21.681, 43.942)  and (45.192, 18.938)

The distance between these points  is

[tex]\sqrt{[ ( 45.192 - 21.681)^2 + ( 43.942 - 18.938)^2 ] } = 34.322 miles[/tex]    (1)

The distance  between (0, 63) and (67, 0)

[tex]\sqrt{[ ( 63)^2 + ( 67)^2 ] }=91.97miles[/tex] (2)

So....you will receive the signal using  (1)/ (2)    

(34.322 / 91.97) x 100  ≈  37%  of the drive

Answer:

The value of f(3) = -2.

Step-by-step explanation:

First of all, let's find f(2).

[tex]f(n+1)=f(n)^{2}-3[/tex]

[tex]f(1+1)=f(1)^{2}-3[/tex]

[tex]f(2)=f(1)^{2}-3=2^{2}-3=1[/tex]

Now, we can find f(3):

[tex]f(2+1)=f(2)^{2}-3[/tex]

[tex]f(3)=f(2)^{2}-3=1^{2}-3=-2[/tex]

Therefore, the value of f(3) = -2.

I hope it helps you!

Answer:

i have seen a lot of racist people. let me tell you something that happened the other day when i was on here i found this kid posting racist things and calling blacks ugly. and he then started being mean to my friends and every year we celebrate black history month for rights rights and this is a good thing to do cause we all matter.#black lives matter

Step-by-step explanation:

Answer:

c

Step-by-step explanation:

;)

Answer:

1.64 meters

Step-by-step explanation:

Subtract 52 - 50.36 to find the difference between the heights. You get 1.64 meters.

Hope it helps!

Step-by-step explanation:

The answer is consistent

9514 1404 393

Answer:

  (x, y) = (8, 2)

Step-by-step explanation:

The relevant equations are ...

  3x -y = 22

  x +2y = 12

__

We can eliminate y by adding twice the first equation to the second.

  2(3x -y) +(x +2y) = 2(22) +(12)

  7x = 56

  x = 8

Substituting into the first equation gives ...

  3(8) -y = 22

  y = 24 -22 = 2

The first number is 8; the second number is 2.

Answer:

-3/5

Step-by-step explanation:

(b + 14)/a = ((-5) + 14)/(-15) = -9/15 =-3/5

Answer:

x = 3.1

Step-by-step explanation:

Subtract 6.3 - 3.2 to find the value of x. You get 3.1.

Hope it helps!

Answer:

????????????????xhrhrhdhehdhzh

Answer:

??????????????????????????????????????????????????????????????????????????///////

Step-by-step explanation:

Answer:

A. base

Step-by-step explanation:

if this helped please press the pink "thanks" button

Answer:

k=63

Step-by-step explanation:

(k/3)+3=24

---> (k/3)=21

- this is because we subtracted 3 from each side

---> k=63

- this is because we multiplied each side by 3

i hope this helped :D

Answer:

k=63

Step-by-step explanation:

i jus checked

Answer:

75+ po e photo math nyo po sa play store I download nyo po

Step-by-step explanation:

sana po makatulong po

Answer:

b trust me its b

Step-by-step explanation:

Answer:

B

Step-by-step explanation:

Took it

Answer:

Step-by-step explanation:

57-2=55

55+7=62

it does not equal 111

Answer:

1 200 000 $

Step-by-step explanation:

(100 divide per 30 ) x 360 000 $