12 is the diameter. We need the circumference which you get by multiplying 12x2 sides which = 24 which is the circumference
Answer:
There are 392 students in the seventh grade.
Step-by-step explanation:
Let us assume that there are x number of students in the seventh grade.
Now, 3/8 of the seventh grade students were taking Advanced math at the beginning of the year, but seven dropped out by the end of the year.
So, after the end of the year there were
number of students taking advanced math.
So, as per given condition, 
⇒ 
⇒ x = 392
Therefore, there are 392 students in the seventh grade. (Answer)
I would say A, even though i am not sure
We can solve this problem by using the laws of exponents. The laws of exponents state:

=

We can use this law in our situation. The answer here, using the laws of exponents, is

or
5.