Option D. 96 is the correct answer.
Explanation:
Let the higher grade be = x
Let the lower grade be = y
As given, The difference of the two grades is 16
or
.... (1)
The sum of one-eighth of the higher grade and one-half of the lower grade is 52.
... (2)
Putting the value of x=16+y in equation (2)
As x=16+y
x=16+80 = 96
Hence, higher grade is 96.
By Green's theorem, the integral of along
is
which is 6 times the area of , the region with
as its boundary.
We can compute the integral by converting to polar coordinates, or simply recalling the formula for a circular sector from geometry: Given a sector with central angle and radius
, the area
of the sector is proportional to the circle's overall area according to
so that the value of the integral is