The venn diagram above represents the students who were sick one day in january at a chicago high school. 80 students had only a fever, 60 students had only a cough, 90 students had only a headache, 10 students had only a cough and fever, 30 students had only a cough and a headache, 40 students had only a fever and a headache, and 20 students had a fever, cough, and headache. 100 students had other reasons for being absent that day. none of the sick students attended school that day. if 800 students attend the high school, how many students were at school that day?

370

Step-by-step explanation:

The venn diagram corresponds to students who were sick in January at a Chicago high school.

Students who had only fever= n(A) = 80

Students who had only headache= n(B) = 90

Students who had only cough  = n(C) =60

Students who had both cough and fever = n(AC) = 10

n(AB) = 40:n(BC) = 30  n(ABC) = 20

Hence total students = 800

no of students who were absent due to other reasons = 100

REmaining students = 700

Students who were sick = sum of all =330

So no of students who were at school = 700-330 = 370

then, the surface area of the sphere shown in the image is: 256π sq. units!

step-by-step explanation:

the lateral surface area of a sphere is 2πrh where h=2r.

then:

surface area = 4πr^2.

in this case, r=8 units ⇒ surface area = 4π(8 units)^2. = 256π sq. units!

then, the surface area of the sphere shown in the image is: 256π sq. units!

step-by-step explanation:

12: 00 p.m. to 7: 00 p.m. is a total of 7 hours.

4: 00 p.m. to 7: 00 p.m. is a total of 3 hours.

this means that from 4: 00 p.m to 7: 00 p.m. this represents 3/7 of what was lost from 12: 00 p.m. to 7: 00 p.m.

after knowing this, after doing 11,600 - 6,800 = 4,800

4,800 represents 3/7 of what was lost for 7 hours.

we then divide 4,800 by 3 which gets 1,600.

because we know that 1,600 represents 1/7 of how much water was lost, we just have to multiply by 7, which gets 11,200.   after adding 11,200 to how much water was left at 7: 00 p.m. which was 6,800. 11,200 + 6,800 = 18,000

this means that the pool originally had 18,000 gallons in the pool.

you can also check your work by doing 18,000 - 4(1600), which becomes           1800 - 6400 which gets you 11,600.