Answer:
Your average would drop to 63.68%. Ask your grader if that is passing.
Step-by-step explanation:
If 10% of your grade is zero, the remaining amount is 90% of 70.76%, ...
0.90·70.76% = 63.684% ≈ 63.68%
The letter grade associated with this depends on class or school standards. Ask your grader what it is.
