This is not an optimal table design for doing what you want in SQL. It would be easier if your table was like this:

userName answerNo answer

test 1 right

test 2 wrong

test 3 right

Then you could use

select count(*) where answer = 'right'

or

select sum(case when answer = 'right' then 1 else 0 end)

As it stands you have to check each column separately with case statements, and sum the results.

select userName,

case when answer1 = 'right' then 1 else 0 end +

case when answer2 = 'right' then 1 else 0 end +

case when answer3 = 'right' then 1 else 0 end +

etc etc