How to compare two queries on two columns in MySQL?

This code will show you a list of questions and whether they were answered correctly.

select
    A.Question,
    min(1) as QuestionsCount,
    -- if this evaluates to null, they got A) the answer wrong or B) this portion of the answer wrong
    -- we use MIN() here because we want to mark multi-answer questions as wrong if any part of the answer is wrong. 
    min(case when Q.idEvaluation IS NULL then 0 else 1 end) as QuestionsCorrect
from
    ExamAnswers as A
    left join ExamQuestions as Q on Q.Question = A.Question and Q.CorrectAnswer = A.ChosenAnswer
group by
    A.Question -- We group by question to merge multi-answer-questions into 1

Output Confirmed:

Note that columns are intentionally named this way, as they should be included as a subquery in part-2 below.

This code will give you a test result.

select
    sum(I.QuestionsCorrect) as AnswersCorrect,
    sum(I.QuestionsCount) as QuestionTotal,
    convert(float,sum(I.QuestionsCorrect)) / sum(I.QuestionsCount) as PercentCorrect -- Note, not sure of the cast-to-float syntax for MySQL
from
    (select
        A.Eval,
        A.Question,
        min(1) as QuestionsCount,
        min(case when Q.idEvaluation IS NULL then 0 else 1 end) as QuestionsCorrect
    from
        ExamAnswers as A
        left join ExamQuestions as Q on Q.Question = A.Question and Q.CorrectAnswer = A.ChosenAnswer
    where 
        A.Eval = 25
    group by
        A.Question, A.Eval) as I
group by        
    I.Eval

Output Confirmed:

. idEvaluation Eval , , .

, sql, SQL, MySQL.