Answer:
20 questions
Step-by-step explanation:
Given
Required
Number of questions answered
First, we need to get the total correct marks obtained by Roy
This is calculated by multiplying the correct marks by number of correct answers
Subtract this from the total scores obtained; This gives the total incorrect answer obtained by Roy
Open bracket
Divide this by -2 to get the number of incorrect answers
Add this to the number of correct answers to give the total number of question answered
<em>Hence, Roy answered a total of 20 questions</em>