M'Lea answered 6 out of 20 questions incorrectly, which means she answered \( 20 - 6 = 14 \) questions correctly.
To find the ratio of incorrect answers to total questions, we can express it as:
\[ \text{Ratio of incorrect to total} = \frac{6}{20} \]
Next, we can simplify this ratio:
\[ \frac{6}{20} = \frac{3}{10} \]
This means that the ratio of incorrect answers to total questions is \( 3:10 \).
Now, we want to find out how many questions M'Lea should answer correctly out of 30 questions. First, we calculate the total questions answered incorrectly based on the ratio:
\[ \text{If there are 30 questions, let } x = \text{number of incorrect answers.} \]
Using the same ratio, we get:
\[ \frac{x}{30} = \frac{3}{10} \]
Cross-multiplying gives:
\[ 10x = 3 \cdot 30 \] \[ 10x = 90 \] \[ x = 9 \]
So, M'Lea would answer 9 questions incorrectly out of 30 questions. Hence, the number of questions she answers correctly is:
\[ 30 - 9 = 21 \]
Therefore, M'Lea should answer 21 questions correctly out of 30 questions.