1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Crazy boy [7]
3 years ago
5

A math class has 3 girls and 9 boys in the seventh grade and 7 girls and 3 boys in the eighth grade. The teacher randomly select

s a seventh grader and an
eighth grader from the class for competition. What is the probability that the students she selects are both girls?
Write your answer as a fraction in simplest form.
Mathematics
1 answer:
vladimir1956 [14]3 years ago
8 0

Answer:

7/40

Step-by-step explanation:

There are 3 girls+9 boys = 12 students in the 7th grade

P (girl in 7th grade) = girls/ total

                                = 3/12 = 1/4

There are 7 girls+3 boys = 10 students in the 8th grade

P (girl in 8th grade) = girls/ total

                                = 7/10

P(7th grade girl, 8th grade girl) = 1/4 * 7/10 = 7/40

You might be interested in
If a biker travels 20 miles in 1 hour how many minutes does it take per miled traveled
Zielflug [23.3K]

1 hour = 60

60min/20miles=3

3 minutes per mile

8 0
3 years ago
I need to transpose the following equation to find the term (g)<br><br> V^2=2gh
nataly862011 [7]
v^2=2gh\\\\2gh=v^2\ \ \ \ |divide\ both\ sides\ by\ 2h\\\\\boxed{g=\frac{v^2}{2h}}
7 0
3 years ago
Read 2 more answers
Find the equation, (f(x) = a(x - h)2 + k), for a parabola containing point (2, -1) and having (4, -3) as a vertex. What is the s
Nataliya [291]

Answer:

f(x)=\frac{1}{2}x^2-4x+5

Step-by-step explanation:

A parabola is written in the form

f(x)=a((x-h)^2+k) (1)

where:

h is the x-coordinate of the vertex of the parabola

ak is the y-coordinate of the vertex of the parabola

a is a scale factor

For the parabola in the problem, we know that the vertex has  coordinates (4,-3), so we have:

h=4 (2)

ak=-3

From this last equation, we get that a=\frac{-3}{k} (3)

Substituting (2) and (3) into (1) we get the new expression:

f(x)=-\frac{3}{k}((x-4)^2+k) = -\frac{3}{k}(x-4)^2 -3 (4)

We also know that the parabola  contains the point (2,-1), so we can substitute

x = 2

f(x) = -1

Into eq.(4) and find the value of k:

-1=-\frac{3}{k}(2-4)^2-3\\-1=-\frac{3}{k}\cdot 4 -3\\2=-\frac{12}{k}\\k=-\frac{12}{2}=-6

So we also get:

a=-\frac{3}{k}=-\frac{3}{-6}=\frac{1}{2}

So the equation of the parabola is:

f(x)=\frac{1}{2}((x-4)^2 -6) (5)

Now we want to rewrite it in the standard form, i.e. in the form

f(x)=ax^2+bx+c

To do that, we simply rewrite (5) expliciting the various terms, we find:

f(x)=\frac{1}{2}((x^2-8x+16)-6)=\frac{1}{2}(x^2-8x+10)=\frac{1}{2}x^2-4x+5

6 0
3 years ago
PLEASE HELP ME!!! The sum of two numbers is 46. When 30 is subtracted from 5 times the smaller the result is 3 times the larger.
Ipatiy [6.2K]

Answer:

m = 21

n= 25

Step-by-step explanation:

the equations are:

n + m= 46

5m-30 = 3n

plz vote brainliest :)

8 0
4 years ago
GEOMETRY PROOFS!
NeX [460]

From the given figure ,

RECA is a quadrilateral

RC divides it into two parts

From the triangles , ∆REC and ∆RAC

RE = RA (Given)

angle CRE = angle CRA (Given)

RC = RC (Common side)

Therefore, ∆REC is Congruent to ∆RAC

∆REC =~ ∆RAC by SAS Property

⇛CE = CA (Congruent parts in a congruent triangles)

Hence , Proved

<em>Additional comment:-</em>

SAS property:-

"The two sides and included angle of one triangle are equal to the two sides and included angle then the two triangles are Congruent and this property is called SAS Property (Side -Angle-Side)

<u>also read similar questions</u>: Complete this proof. Given: EC AC, DB AC, ∠A = ∠F Prove: ΔMDF ∼ ΔNCA..

brainly.com/question/16250124?referrer

Consider the proof. Given: Segment AB is parallel to line DE. Prove: AD/DC = BE/EC What is the missing statement in Step 5? A.) AC = BC B.) AC/DC = BC/EC C.) AD...

brainly.com/question/11763540?referrer

6 0
2 years ago
Other questions:
  • Just number 16 please<br> thank you sooooooo much
    5·1 answer
  • How to find simple interest rate?
    14·2 answers
  • What is the average rate of change from x = 0 to x = 4?
    7·1 answer
  • Maggie's brother is 4 years younger than four times her age. The sum of their ages is 26.
    5·1 answer
  • What is the value of f(3)?
    11·1 answer
  • And a wildlife preserve 46 ducks are captured tagged and then released. Later to her ducks are examined in four of the 200 ducks
    8·1 answer
  • PQRS is a trapezoid with a right angle. What are the coordinates of S
    6·1 answer
  • P + 0.20p as an equivalent expression
    9·1 answer
  • Find the value of x.
    10·1 answer
  • Which inequality is equivalent to |x-4| less than 9? –9 &gt; x – 4 &lt; 9 –9 &lt; x – 4 &lt; 9 x – 4 &lt; –9 or x – 4 &lt; 9 x –
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!