Answer: 95%
Explanation:
To obtain score of 80% on entire exam means the student have to answer
(80/100)×80 = 64 correct answers
Student have already answered 75% of the first 60 questions correctly meaning
(75/100)×60=45 correct answers from first 60 questions
Remaining correct answers s/he have to answer
64-45=19
So from remaining 20 questions s/he have to answer 19 correct questions that is
20 × (x/100) = 19
x = 19 ×(100/20)
x = 95%
