Solution
Correct Answer: Option C
Here, 80% of 80 question= 80 X 80/100 =64 so ,he needs to answer total 64 question correctly now, as he answered 75% of 60 question correctly=75/100 x 60 =45 so, remaining question=64-45=19 to answer total 64 question and 19 of 20 =19/20 x 100=95%