If mark got 6 questions out of 40 incorrect what percent of the questions did he get correct?

The answer is 85% and this is how it can be calculated:
Total correct answer= 40- incorrect
Total correct answer= 40 - 6
34/40= 0.85 or 85%
The other way of finding the answer is that, First find the percentage of incorrect and then deduct it from 100%. Like
6/40 = 15%
Percentage of Correct answers= 100%-15% = 85%

So u know that if mark got 6 questions incorrect, then u would have to subtract 6 marks from the overall amount of marks, which is 40. so, if we subtract 6 from 40, the answer would be 34-which is the amount of questions he did correctly.

so u have to put the amount of questions he got correct over the amount of questions there were in the test and multiply that by 100, so it would be:

34/40*100=3400/40=85%

thus, Mark got a total study mark of 85% in the test (these questions are can get complicated, and financial stuff can confuse students, but if u follow the steps correctly and think in context to the question, u will not struggle to deal with these questions) I hope i helped:)