you have to add 90 +90 3 times then theres your answer :)
Answer:
100%
Step-by-step explanation:
Use conditional probability:
P(B | A) = P(B and A) / P(A)
P(B | A) = (12/28) / P(A)
We need to find the probability that a student studies art.
P(A or B) = P(A) + P(B) − P(A and B)
24/28 = P(A) + (12+12)/28 − 12/28
P(A) = 12/28
P(B | A) = (12/28) / (12/28)
P(B | A) = 1
What this means is that all of the students who study art also study biology.
The altitude of a triangle is a line segment through a vertex and perpendicular to a line containing the side opposite the vertex.
Answer: 
<em>Part A: </em>
Let c represent the total amount of chocolate there is in lbs.
c = 0.25c + 0.75c
<em>Part B: </em>
0.75c represents milk chocolate, and we know that there are 3 lbs of milk chocolate, so you can replace the 0.75c with 3 (representing 3 lbs):
c = 0.25c + 3
Divide all the terms by c:
1 = 0.25 + 3/c
Subtract 0.25 from both sides to combine the like terms:
0.75 = 3/c
Multiply all the terms by c to make the equation easier to work with:
0.75c = 3
Divide both sides by 0.75 to isolate the c and find the total amount of chocolate in pounds.
c = 4
Substitute c for 4 in the term that defines dark chocolate (which was 0.25c)
0.25(4) = 1 pound
Therefore, there was exactly 1 pound of dark chocolate present in the chocolate.
This makes sense, as 1 pound of dark chocolate + 3 pounds of milk chocolate = 4 pounds of chocolate in total, and 1 is 25% of 4 and 3 is 75% of 4.