Option D. 96 is the correct answer.
Step-by-step 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)
![(16+y)/(8)+(y)/(2)=52](https://img.qammunity.org/2019/formulas/mathematics/high-school/zj9a4pt0e2va2pw4jqc8lv8fz0amul0le8.png)
![(16+y+4y)/(8)=52](https://img.qammunity.org/2019/formulas/mathematics/high-school/xb50sd8log87t8wf508by44f0lea9yjn9o.png)
![(16+5y)/(8)=52](https://img.qammunity.org/2019/formulas/mathematics/high-school/veviueypvmsy6xjtzs4t0gsrdq4s63xycl.png)
![16+5y=416](https://img.qammunity.org/2019/formulas/mathematics/high-school/euoquda1p2ngjqxodqaftcrkvmp6ho2l44.png)
![5y=400](https://img.qammunity.org/2019/formulas/mathematics/high-school/9vo4s59ahpknhlvo2cf1k6f4e7w0ugwne4.png)
![y=80](https://img.qammunity.org/2019/formulas/mathematics/high-school/1hhoryc9y3rfxo9tomaj2sqc9x9zqhlmr1.png)
As x=16+y
x=16+80 = 96
Hence, higher grade is 96.