Marks scored = +110
So, minimum correct responses
= 110 ÷ (+5) = 22
Case 1
Correct responses = 22
Marks for 1 correct response = + 5
Marks for 22 correct respones
= +110 (22 × 5)
Marks scored = +110
Marks obtained for incorrect answer = 0
So, no incorrect response
And, therefore, 3 were unattempted
Case 2
Correct responses = 23
Marks from 23 correct responses
= + 115 (23 × 5)
Marks scored = + 110
Marks obtained for incorrect answers
= 110 – (+115)
= –5
Marks for 1 incorrect answer = –5
Number of incorrect responses
= (–5) ÷ (–5)
= 1
So, 23 correct, 1 incorrect and 1 unattempted.
Case 3
Correct responses = 24
Marks from 24 correct responses = + 120 (24 × 5)
Marks scored = + 110
Marks obtained for incorrect answers = +110 – (+120)
= –10
Number of incorrect responses
= (–10) ÷ (–5) = 2
Thus the number of questions = 24 + 2 = 26. Whereas,
total number of questions is 25. So, this case is not
possible.
So, the possible ways are:
• 22 correct, 0 incorrect, 3 unattempted
• 23 correct, 1 incorrect, 1unattempted.