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2 years ago

It was 9/20 ..

Mathematics

1 answer:

Elza [17]2 years ago

6 0

Answer:

$\frac{9}{20}$

Step-by-step explanation:

We want probability that 1st is girl AND 2nd is girl as well.

In probability "AND" means multiplication and "OR" means "addition".

We find the probabilities separately and multiply them together, since "AND".

P(girl from 7th grader) = number of girl 7th grader/total number of 7th grader

=9/10

P(girl from 8th grade) = number of girl in 8th grade/total number of 8th grader

=2/4

P(both girls) = 9/10 * 2/4 =9/20

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Pass through (1,2) and (3,1)

ludmilkaskok [199]

Answer:

$y=-\frac{1}{2}x+\frac{5}{2}$

Step-by-step explanation:

slope = -1/2

y - int. = 5/2

good luck, i hope this helps :)

7 0

2 years ago

Joe has eaten 2/5 of a pizza.Jane has eaten 1/6 of a pizza how many more pizza has joe eaten than Jane?

jenyasd209 [6]

Joe ate 7/30 more of pizza than Jane. You can just subtract 2 uneven denominators. So you would turn them into 30 because that’s the closest highest number that can go with 5 and 6. Then multiply 2 with 6 which is 12 and then multiply 1 with 5 which is 5 now you can subtract it. 12/30-5/30=7/30.

Final Result: 7/30

3 0

2 years ago

Do the three points lie on one line?

padilas [110]

Answer:

Yes. No graph paper.

Step-by-step explanation:

Let's say the 3 points are A, B, C.

If A, B and C lie on one line then $m_{AB} = m_{BC} = m_{AC}$

$m_{AB} = \frac{y_{B}-y_{A} }{x_{B}-x_{A}} = \frac{2-6}{3-5} = \frac{-4}{-2} = 2\\m_{BC} = \frac{y_{C}-y_{B} }{x_{C}-x_{B}} = \frac{8-2}{6-3} = \frac{6}{3} = 2\\\\m_{AC} = \frac{y_{C}-y_{A} }{x_{C}-x_{A}} = \frac{8-6}{6-5} = \frac{2}{1} = 2\\\\$

Hence, they lie on one line.

You don't need to use a graph paper to prove it.

4 0

1 year ago

Solve for a side triangles please help it’s urgent please answer

rodikova [14]

Answer:

AC ≈ 2.87

Step-by-step explanation:

Using the sine ratio in the right triangle

sin35° = $\frac{opposite}{hypotenuse}$ = $\frac{AC}{AB}$ = $\frac{AC}{5}$

Multiply both sides by 5

5 × sin35° = AC , thus

AC ≈ 2.87 ( to the nearest hundredth )

7 0

2 years ago

A plane flew 360km in 3 hrs when flying with the wind.With no change in the wind,the return trip took 4 hrs.Find the speed of th

morpeh [17]

Speed of the plane: 250 mph
Speed of the wind: 50 mph
Explanation:
Let p = the speed of the plane
and w = the speed of the wind
It takes the plane 3 hours to go 600 miles when against the headwind and 2 hours to go 600 miles with the headwind. So we set up a system of equations.
600
m
i
3
h
r
=
p
−
w
600
m
i
2
h
r
=
p
+
w
Solving for the left sides we get:
200mph = p - w
300mph = p + w
Now solve for one variable in either equation. I'll solve for x in the first equation:
200mph = p - w
Add w to both sides:
p = 200mph + w
Now we can substitute the x that we found in the first equation into the second equation so we can solve for w:
300mph = (200mph + w) + w
Combine like terms:
300mph = 200mph + 2w
Subtract 200mph on both sides:
100mph = 2w
Divide by 2:
50mph = w
So the speed of the wind is 50mph.
Now plug the value we just found back in to either equation to find the speed of the plane, I'll plug it into the first equation:
200mph = p - 50mph
Add 50mph on both sides:
250mph = p
So the speed of the plane in still air is 250mph.

6 0

2 years ago