Answer:

And then replacing in the total probability formula we got:

And rounded we got 
That represent the probability that it rains over the weekend (either Saturday or Sunday)
Step-by-step explanation:
We can define the following notaton for the events:
A = It rains over the Saturday
B = It rains over the Sunday
We have the probabilities for these two events given:

And we are interested on the probability that it rains over the weekend (either Saturday or Sunday), so we want to find this probability:

And for this case we can use the total probability rule given by:

And since we are assuming the events independent we can find the probability of intersection like this:

And then replacing in the total probability formula we got:

And rounded we got 
That represent the probability that it rains over the weekend (either Saturday or Sunday)
Hey there,
All we have to do is 472-21=451
So your number would be 451
Answer:
The frequency of the note a perfect fifth below C4 is;
B- 174.42 Hz
Step-by-step explanation:
Here we note that to get the "perfect fifth" of a musical note we have to play a not that is either 1.5 above or 1.5 below the note to which we reference. Therefore to get the frequency of the note a perfect fifth below C4 which is about 261.63 Hz, we have
1.5 × Frequency of note Y = Frequency of C4
1.5 × Y = 261.63
Therefore, Y = 261.63/1.5 = 174.42 Hz.
Answer: yes , it is possible
Step-by-step explanation:
Let the first number be x and the second number be y .Then , the sum of the two numbers will be x + y , and their difference will be x - y.
Combining the two , we have :
x + y = 1 ............................... equation 1
x - y = 8 ................................. equation 2
solving the system of linear equation by substitution method. From equation 1 , make x the subject of the formula ,
x = 1 - y ...................... equation 3
Substitute equation 3 into equation 2 ,
1 - y - y = 8
1 - 2y = 8
add 2y to both sides
1 = 8 + 2y
subtract 8 from both sides
1 - 8 = 2y
- 7 = 2y
divide through by 2
y = 
y = - 3.5
substitute y = -3.5 into equation 3 to find the value of x , we have
x = 1 - y
x = 1 - ( - 3.5 )
x = 1 + 3.5
x = 4.5
Let us check :
x + y will be
4.5 + (-3.5) = 1
Also ,
x - y will be
4.5 - (-3.5)
⇒ 4.5 + 3.5 = 8
Answer:B: 36°
Step-by-step explanation:
We know that ∆ABC is isoceles, making (angle)<ABC and <BCA congruent because base angles of isoceles triangles are congruent.
Because we have parallel lines, we can look for alternate interior angle pairs. <BCA is congruent to <DAC because they're alternate interior angles.
If <BCA is x then so is <ABC.
Since triangles add up to 180° we can add all of the angles (3x+x+x) and set it equal to 180.
3x+x+x=180
5x=180
x=36
If we were looking for <BAC we would plug that back in and solve, but we're looking for <BCA which is equal to x, therefore m<BCA=36°