Answer:
Option D is correct.
Step-by-step explanation:
In triangle ADE and triangle ABC
From the figure:
[Angle] [Given]
[Angle]
AA(Angle-Angle) similarity criterion states that in two triangles if two pairs of corresponding angles are equal, then these triangle Similar.
By AA similarity:
⇒
Answer:
Q1) The student has a 0.01% probability of passing the test.
Q2) She has a 99.91% probability of passing in the test.
Step-by-step explanation:
For each question, there are only two possible outcomes. Either he gets it correct, or he gets it wrong. So we solve this problem using the binomial probability distribution.
Binomial probability distribution
The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.
In which is the number of different combinatios of x objects from a set of n elements, given by the following formula.
And is the probability of X happening.
For this problem, we have that:
Question 1.
There are 50 questions, so .
The student is going to guess each question, so he has a probability of getting it right.
He needs to get at least 25 question right.
So we need to find .
Using a binomial probability calculator, with and
we get that
.
This means that the student has a 0.01% probability of passing the test.
Question 2.
Now, we need to find with
. So
She has a 99.91% probability of passing in the test.
Answer:
x=5, y=2
Step-by-step explanation:
To solve this system, we need to find x and y. First, let's find x. In the first equation (6x+4y=42), subtract 4y on both sides to isolate 6x. This will result in 6x=42-4y. Divide by 6 on both sides to isolate x and get x=7-y. Now we know what x equals. Go to the second equation ad plug this into it. So instead of -3x+3y=-6, you'll have -3(7-
y)+3y=-6. Use the distributive property to get -21+2y+3y=-6. Add 2y and 3y to get -21+5y=-6. Add 21 to both sides to isolate 5y and get 5y=15. Divide by 5 on both sides to isolate y and get y=3. Now that we know that y=3, we can plug this back into the equation that was bolded above so that we can find x, so we'll have x=7-
(3) since y=3, and we'll get x=7-
, or x=7-2, or x=5.
x=5
y=2