Answer:
81
Step-by-step explanation:
27 total of pupils.
girls 1×27=27
boys 2×27=54
total 54+27=81
This makes no sense srry, rephrase it correctly pls in order for me to answer it :P
Answer:

Step-by-step explanation:
The Universal Set, n(U)=2092


Let the number who take all three subjects, 
Note that in the Venn Diagram, we have subtracted
from each of the intersection of two sets.
The next step is to determine the number of students who study only each of the courses.
![n(S\:only)=1232-[103-x+x+23-x]=1106+x\\n(F\: only)=879-[103-x+x+14-x]=762+x\\n(R\:only)=114-[23-x+x+14-x]=77+x](https://tex.z-dn.net/?f=n%28S%5C%3Aonly%29%3D1232-%5B103-x%2Bx%2B23-x%5D%3D1106%2Bx%5C%5Cn%28F%5C%3A%20only%29%3D879-%5B103-x%2Bx%2B14-x%5D%3D762%2Bx%5C%5Cn%28R%5C%3Aonly%29%3D114-%5B23-x%2Bx%2B14-x%5D%3D77%2Bx)
These values are substituted in the second Venn diagram
Adding up all the values
2092=[1106+x]+[103-x]+x+[23-x]+[762+x]+[14-x]+[77+x]
2092=2085+x
x=2092-2085
x=7
The number of students who have taken courses in all three subjects, 
Answer:
0.49
Step-by-step explanation:
We apply conditional probability to solve this question.
We have Events X and Events Y
P(X) = Probability Christine fails the course = ??? Unknown
P(Y) = Probability Christine finds a tutor
= 0.35
P(Y') = Probability Christine does not find a tutor = 1 - 0.35 = 0.75
P(X|Y) = Decrease in her probability of failing = 0.35
P(X|Y') = Probability that she will fail the course if she does not have a tutor
P(X) = P(X|Y) × P(Y) + P(X|Y') × P(Y')
P(X) = 0.35 × 0.75 + 0.65 × 0.35
P(X) = 0.2625 + 0.2275
P(X) = 0.49
The probability that Christine fails the course is 0.49
First take 18 and divide by 50 = .36, so your percent is 36%.