To find the percentage for 7 marks out of 20, you can use the formula:

$\text{Percentage} = \left(\frac{\text{Obtained Marks}}{\text{Total Marks}}\right) \times 100$

Substitute the given values:

$\text{Percentage} = \left(\frac{7}{20}\right) \times 100 = 35\%$

So, the percentage is 35%.

Would you like further details or have any questions?

Here are 5 related questions to deepen your understanding:

1. How would you calculate the percentage for 12 out of 30 marks?
2. What percentage do you get if you score 18 out of 25?
3. How does increasing the total marks affect the percentage score?
4. What is the percentage of getting 50 marks out of 200?
5. If you score 15 out of 50, what would your percentage be?

Tip: When calculating percentages, always ensure the numerator (obtained marks) is divided by the denominator (total marks) before multiplying by 100.