We know that the total number of students is 180, so 180 is the 100 precent of the students, now we can set up a proportion and solve
180/100=135/x
x=135 times 100 over 180
x=75%
Answer:
C
Step-by-step explanation:
If the flask shown in the diagram can be modeled as a combination of a sphere and a cylinder, then its volume is

Use following formulas to determine volumes of sphere and cylinder:
wher R is sphere's radius, r - radius of cylinder's base and h - height of cylinder.
Then
Answer 1: correct choice is C.
If both the sphere and the cylinder are dilated by a scale factor of 2, then all dimensions of the sphere and the cylinder are dilated by a scale factor of 2. So
R'=2R, r'=2r, h'=2h.
Write the new fask volume:

Then

Answer 2: correct choice is D.