If you plan to attempt 80 questions, a score target depends on how many of those answers are correct and how wrong answers are penalised. The unanswered part of the paper does not add marks in this model.
Correct Answers Needed finds the smallest whole correct answer count that meets the target under those declared conditions. It does not recommend guessing or estimate your likely accuracy.
Fix the attempted count first
Enter the total number of questions and the number you plan to attempt. Attempted questions cannot exceed the paper total.
Each attempted answer is treated as either correct or wrong. That assumption matters: the tool does not model partial credit, multiple score bands or sections with different rewards.
Add the marks earned per correct answer and the deduction per wrong answer from the paper instructions. A zero penalty is allowed where the marking scheme has no deduction.
Sixty net marks from 80 attempts
Suppose the paper has 100 questions, you attempt 80, correct answers earn one mark, and wrong answers lose a quarter mark. Set the target to 60 net marks.
With 64 correct answers and 16 wrong answers, the score is 64 minus four, giving 60. With only 63 correct, the other 17 attempted answers are wrong, producing 58.75.
The minimum correct answer count is therefore 64. The calculator rounds upwards because a fraction of an answer cannot satisfy the count model.
What an unreachable target looks like
Attempting 80 questions at one mark each can earn no more than 80 marks, even with every answer correct. A 100 mark target is unreachable under that attempt plan.
The tool still shows the mathematical correct count required, but explains when it exceeds your planned attempts. A number larger than the attempted count is not a possible outcome for that plan.
Compare plans without changing the rules
You can change attempted count to inspect another scenario. Keep reward and penalty fixed if you are comparing plans for the same paper. Otherwise the difference may come from the changed marking scheme rather than the plan.
After a practice test, enter actual counts in Negative Marking Score to check the achieved score. That result can help you assess how realistic your target accuracy is.
Use Exam Time Per Question separately for time allocation. Having enough planned attempts does not establish that there will be enough paper time to complete them.