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.