Answer:
21 students
Step-by-step explanation:
25% of 28 is 7 28-7=21
Answer:
24 units
Step-by-step explanation:
Given is a circle with two chord BE and CD
BE and CD intersect at A
By circle chords intersection theorem we have
DA*AC = EA*AB
i.e. 8(15) = 5(AB)
Divide by 5 both the sides
AB =8(15)/5 = 8(3) = 24 units
Verify:
Let us check now whether chord intersection theorem is satisfied.
DA*AC = 8(15) = 120
EA*AB = 5(24) = 120
Since these two equal, we verify that answer is right.
Answer: 88
Step-by-step explanation: 77+82+73= 232. So you need an 80 for average. So what you have to do is 80x4 and that equals to 320. last step is to subtract 320-232 and you get 88. 77+82+73+88=320.
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, 